Chapter 1

Mission: Under One Roof

“…Aah…,” Shido sighed.

He plodded along the residential street at the pace of an old man with bad knees as the sun began its journey back to the horizon. His face was haggard with exhaustion, and the hair that hung over his eyes was dull and lifeless. He was only sixteen but looked much older.

And who could blame him?

“…Aah.” Another sigh.

Tohka and Origami kept going at each other, and he stepped in to stop them every time. This wasn’t the first of these fights. They’d been happening almost daily since Tohka transferred to Raizen High, the public school Shido attended. If it were the bickering of two teenage girls, he wouldn’t have been as anxious as he was.

“…”

He cast his mind back to Tohka and Origami in their forms he witnessed last month. One a Spirit, a world-ending catastrophe. The other, a wizard with the Ground Self-Defense Forces Anti-Spirit Team. Both in possession of superpowers far beyond the human domain.

An average guy, Shido was constantly put in the position of trying to stop them from ripping each other’s faces off. On top of physical exhaustion, he was on the verge of mental collapse.

“Can’t they get along for five seconds…?” he grumbled, then shook his head at his own idiocy.

Until a month ago, the two girls had been literally trying to kill each other. The “commander” said Origami and the rest of the AST wouldn’t come for Tohka because they weren’t getting a Spirit signal from her. Even so, she wasn’t exactly champing at the bit to become best friends with the now-powerless Spirit.

Shido wouldn’t last much longer if things kept up the way they were. He was about to sigh even longer and louder when he jerked his head up.

“…Hmm?” He felt something cold trail down his neck. “…Gah.” He scowled at the sky.

At some point, it had turned leaden with clouds.

“Rain? Give me a break! The forecast said it was going to be sunny,” he muttered to himself, cursing the weather forecaster, who was more miss than hit these days.

As though the sky had been waiting for that very moment, fat droplets started to mark out dark spots on the pavement.

“Yikes…” He held his bag up over his head and trotted toward his house.

The rain started to come down harder, as if to mock his efforts, and turned into a downpour.

“Oh, come on. Seriously…?” He frowned in annoyance, cold rain seeping into his skin through his wet uniform.

His first thought wasn’t about how uncomfortable the uniform felt plastered to his skin or about catching a cold, but the somewhat domestic anxiety of whether his blazer would be dry in time for school the next day. Which was perhaps only natural, given that Shido was taking care of all the chores while his parents were away for work.

He started to run down the road, trying in vain to keep his uniform from getting totally soaked. Right when he was about to turn at the T-intersection, his feet stopped abruptly.

“Uh…?”

It wasn’t that he was simply too tired to go on or he’d decided he was fine with being wet. Something had appeared just up ahead, which he found much more interesting than beads of water falling from the heavens.

“Is that…a girl?” he asked.

Yes. A girl. A small shadow wrapped in a cute cloak. He couldn’t see her face because a large hood with decorative rabbit ears hid it completely from view. Even more curiously, on her left hand was a ridiculous rabbit puppet.

This girl bounced around the deserted road, looking like she was having the time of her life.

“What…?” He stared at her, frowning as a question popped inside his head.

He wasn’t curious about why she would be bouncing around in the rain without an umbrella, but why? What about her had so instantly commanded his attention?

Her outfit was indeed eye-catching. But that wasn’t it.

He couldn’t quite put the feeling into words, but it was like something was out of place, a strange, uncanny sensation. He felt almost certain he’d experienced this before and very recently, at that.

“…”

The chill of the rain and the clamminess of his wet uniform didn’t bother him anymore. His eyes were fixed on the girl dancing beneath the stormy sky.

Fwoosh! Thud!

“Huh…?” His eyes snapped open as the girl tripped.

She slammed into the ground face-first, sending droplets of water up into the air. The puppet on her left hand broke free and flew off ahead of her. She lay on the road, motionless.

“…H-hey!” He sprinted over to her and cradled the small body. He turned her over. “Y-you okay? Hey!”

At last, he saw the girl’s face. She was probably about the same age as his little sister, Kotori, but her fluffy hair was blue like the ocean. Her soft lips were the color of cherry blossoms, and she was as beautiful as a porcelain doll.

“…!” Her eyelids sprang open to reveal sapphire eyes surrounded by long lashes.

“Aah, thank heavens… Are you hurt?” he asked.

All the color drained out of the girl’s face, eyes darting around, and she leaped up and out of his arms. Once she had put some distance between the two of them, she shivered and sent a fearful glance his way.

“…Umm.” He guessed it had maybe been a little imprudent to touch her, even if he’d only been trying to help. That said, he hadn’t expected she would react this way. “I-I’m—”

“Eek! S-stay…back…please!” the girl squeaked in a frightened voice.

“Huh?” He took a step forward.

“Please…don’t…hurt me…” She shivered like a small animal in the rain, fearful of the threat Shido apparently presented.

“Umm…” He wasn’t sure how to react until he noticed the puppet on the ground. It had slipped off her hand when she fell. He slowly bent over to pick it up and offered it to her. “Is this…yours?”

“…!” She opened her eyes wide and started to race over to him but quickly stopped again. As she carefully eyed the distance between them, the look on her face said she wanted her puppet back, but she was also afraid to get too close to Shido.

He smiled a little and inched toward her, holding it out to her.

“…!” She trembled, but at last, she seemed to understand what he intended to do, and her own feet started to move slowly in his direction.

When she was close enough, she snatched the puppet from his hand and stuffed it onto her own, making its mouth move.

“Whoa there, buddy. You really helped me out.” The rabbit spoke in a curiously high-pitched voice, through ventriloquism, Shido supposed.

Cocking his head curiously to one side, Shido looked doubtfully at the girl’s face, but the rabbit kept going, as if to stop him from saying anything to the girl.

“So when you picked me up there, you ended up touching a whole lot of Yoshinon. How’d you like it? C’mon, be honest. You can tell me.”

“Uh…?” he said.

“Playing dumb, huh, you lucky perv.” The puppet rocked back and forth, like it was trying to show it was laughing. “Well, you did help me out there, so I’ll let it slide this once.”

“…Uh, okay. Sure.” He offered a pained smile.

“Mmkay, then. Thanks muchly,” the puppet chirped, and the girl whirled around and sprinted off.

“H-hey!” he called out, but the girl didn’t so much as look back at him. She raced around the corner and out of sight.

“What was that…?” He stood rooted to the spot for a few seconds, scratching his cheek, dumbfounded.

“Oh!” He had been so focused on the girl, he hadn’t noticed that he was drenched to the bone. Plus, he’d knelt down on the ground, so his trousers were dirty to boot. “Gah. Just my luck…”

Do we have any stain remover left? he wondered as he ran a hand through his hair. Droplets of water flew into the air.

Now that he was this wet, there was no point in hurrying anymore. He aired out his grievances with a sigh and started toward his house. “Aah… I’m soaked,” he grumbled.

He reached his house at last and put his key into the lock and then frowned slightly. “…Hmm?”

He grabbed the knob and pulled. Just as he’d expected, the door he knew he’d locked when he went out opened without any resistance.

“Dammit, Kotori.” He sighed. “I guess she’s finally back?”

His little sister, Kotori Itsuka. Thirteen years old, in her second year at the local junior high school. Also the commanding officer of Ratatoskr, an organization that worked to neutralize the Spirits through peaceful means.

She’d been so swamped with work in the aftermath of taking the Spirit Tohka into protective custody that she hadn’t been home for a month.

“Honestly,” he groaned, her face popping up in the back of his mind. He understood she was busy with the whole Tohka thing, but he couldn’t turn a blind eye to the fact that she didn’t have permission to be away from home. It seemed like she’d been going to school, at least. But as her older brother, it was his duty to say something to her.

“And—”

He swallowed hard. He had a lot of questions for her. Everything that had happened to him last month seemed impossible now, like something out of a dream. And Kotori was at the center of it all.

“…” His heart started to pound, even though he was just going to talk to his little sister.

“Raaah!” He puffed up his cheeks, braced himself, and stepped into the house. “I’m home!”

He took off his rain-soaked shoes and socks and rolled up the hems of his trousers before stepping up into the house, leaving wet footprints in his wake.

He could hear the TV down the hallway. So Kotori was in the living room.

Shido changed course for the bathroom on tiptoes. He couldn’t exactly talk to her in this drowned-rat state. It would be best to dry himself off and change clothes before heading into the living room.

With his schoolbag in one hand, Shido opened the door to the changing area that led into the bathroom with a practiced move…and froze in place.

“—?!”

There was a girl in the changing area who should not have been there.

Long hair the color of night spilling down her back, eyes like crystals. She was so gorgeous, her presence so powerful, that the superlative most ten times in a row wouldn’t begin to describe even a tenth of her beauty.

Shido knew of only one such girl. A Spirit, a world-ending catastrophe. And Raizen High School, Year 2, Class 4, student ID #35.

Tohka Yatogami was standing in front of him. Without a single thread of clothing on her body.

“T-Tohka…?” he murmured, stunned.

Her body, a work of art in and of itself, instantly caused Shido’s retinas, nerves, brain cells to vibrate, evaporate, explode. Breasts comfortably cupped in a hand, a waist that darted in below them, a soft butt. A bewitching and mysterious nude body that would no doubt push the girls of the world beyond envy and on to something akin to reverence.

“Wha—?!” She jumped and looked over at him. “Sh-Shido?!”

“Oh! Uh! No! It’s not! …I just—!” He didn’t know what it wasn’t, but the words spilled heedlessly from his mouth.

“Wh-whatever…!” she cried. “Just get out!”

“Hngh…!” He took an impossibly perfect right straight to the solar plexus and staggered backward until he hit the wall. He slid down to the floor.

Slam! Not a heartbeat later, the door to the changing area banged shut.

“—Nnrgh. Ugh… Sh-she actually hit me for real…,” he choked out, coughing, and then made a slight revision to that statement. If Tohka had hit him for real, his body would have collapsed into a handy foldable version of himself, neatly storable in a drawer.

Gradually, the pain in his gut subsided, and the skin-colored image that ate into his brain and retinas faded. He managed to get the pounding of his heart back under control.

The door to the changing area opened a crack, and Tohka’s beet-red face peeked out. “…Did you see anything, Shido?!”

“…!”

He shook his head vigorously back and forth as Tohka stared him down. The truth was, he had seen something, but if he was stupid enough to come clean, he really would be bent into a new shape small enough to fit in a suitcase.

“Hmm…,” she said, perhaps satisfied with this, and opened the door the rest of the way.

Naturally, she was wearing clothes now, but she wasn’t in her school uniform. Instead, she was clad in his own favorite loungewear, lent to her by Kotori, he assumed. His clothes were a size too big for her, and her collarbone was peeking out of the collar, which was strangely hot. Shido wasn’t exactly sure where to rest his eyes.

But this was no time to worry about that. He stabbed a finger at her. “Wh-what are you doing in my house, Tohka…?!”

“What?” She frowned, like she had no idea why he was asking her that. “Your sister didn’t tell you? She said I should stay over for a while for some kind of training or something.”

“T-training…?!” Now he frowned and turned his gaze down the hallway.

He got to his feet, marched to the living room, and yanked open the door. “Kotoriiii! Explain yourself!”

“Uh?” The pigtailed child sitting on the sofa watching TV looked over her shoulder with eyes round like walnuts. “Oh, hey, Big Bro. You’re home.”

“Y-yeah, just got ba—There isn’t time for that!” He almost answered her like everything was normal before shaking his head furiously. “Did you bring Tohka over…? What exactly is this ‘training’…?!”

“Settle down.” She waved a distracted hand at him.

“How am I supposed to settle down?!” he shrieked. “Wh-why is Tohka here…? Wasn’t she supposed to go home with Reine?”

“Huh? Oh, her.” Kotori pointed toward the kitchen.

“Huh…?” Shido turned his eyes in that direction and froze again.

“…I stopped by for a bit.” An extremely sleepy woman was seated at the dining table separating the living room from the kitchen, dropping sugar cube after sugar cube into a steaming mug.

Reine Murasame. Ratatoskr analyst and Shido’s assistant homeroom teacher. She was not in her usual garb of military uniform or lab coat but rather in his mother’s pajamas with a towel wrapped around her neck. Her hair looked a little damp.

“R-Reine?” He gaped. “What are you doing?”

“…Mm?” Reine appeared to sink into thought briefly and then tousled the back of her head. “Oh, sorry. Did I use too much sugar?”

“That’s not what I meant!” he shouted in frustration. It was true that she had put in so many sugar cubes that he worried she might have diabetes in the future, but that wasn’t the issue at the moment. He patted his chest to calm his racing heart. “What’s going on here? Doesn’t Tohka live on Fraxinus?!”

Now in the custody of Ratatoskr, Tohka lived in a separate area inside Fraxinus, the airship owned by the organization, while she attended school. Her power might have been sealed away, but she was still a Spirit, often referred to as a living natural disaster. So a room on the ship had been prepared for her in a closed-off area that was strictly sealed, allowing Ratatoskr to respond immediately in case anything happened and efficiently carry out regular exams. Thus, at the end of the school day, Tohka usually returned to Fraxinus with Reine.

“…Ohhh, yeah. I guess that needs an explanation,” Reine said, rubbing eyes adorned with dark bags. “…But before that.”

“Before that…?” he parroted.

“…Shouldn’t you change? You’re dripping on the floor.”

“Ah!” he cried out softly.

“…So? What exactly is going on here?”

Now in fresh, dry clothes, Shido turned his gaze on Kotori and Reine, who were sitting across from him in his little sister’s room on the second floor of the Itsuka home. Big enough to squeeze in only six tatami mats, the small room was furnished with a pastel-colored dresser and bed, with fancy accessories and stuffed animals crammed into every available space.

He would have preferred to continue the conversation in the living room, but they would be talking about some things Tohka was better off not hearing, so they’d taken the discussion upstairs. Tohka, meanwhile, was engrossed in a rerun of some anime in the living room. She wouldn’t be making a peep for the next twenty minutes at least.

“Mmkay.” Kotori poked her cheek with a finger. “Tohka’s going to be living here for a while—as of today!” She puffed her chest out, pleased as punch, an innocent smile on her face.

“And I’ve been trying to ask you whyyyyyy!” Shido shouted.

“…Mm, well, calm down, Shintaro,” Reine cooed.

Just as he’d feared or maybe expected, she still had his name wrong.

“It’s not Shintaro, it’s Shido,” he corrected.

“…Oh, right. I’ll fix that. Sorry, Shin.”

“…”

Nothing had been fixed. She’d just shortened her nickname for him. He could only assume she was doing it on purpose. When he looked at her dazed face, however, it did actually look like she was aware of her mistake. But he didn’t have time to follow up on the issue of his name now.

“…Broadly speaking, there are two reasons,” Reine began in a quiet voice. “One. It’s for Tohka’s aftercare.”

“Aftercare…?” he repeated.

“…Shin. Remember you sealed Tohka’s power with a kiss last month?”

“…Uh-huh…” He dropped his gaze as he felt the kiss all over again on his lips. His face reddened.

“Ooh, my big brother’s turning red!” Kotori squealed, sounding like she was having the time of her life. “How adorable.”

“Sh-shut up!” He looked away.

“…Well, that was great and all, but there’s one problem… Now you’ve got this invisible Path running between you and Tohka.”

“A Path?” He frowned. “What does that mean?”

“…Put simply, when Tohka’s mental state becomes unstable, the Spirit power sealed in your body could potentially flow back into her.”

“Wha—?” He felt a shiver run up his spine.

Tohka’s sealed Spirit powers flowing back into her…? Did that mean she would be equipped with the power to rip asunder heaven and earth again? Just thinking about it made his hair stand on end.

“…As you also know, Tohka’s living in a separate area of Fraxinus right now,” Reine continued, ignoring or unaware of Shido’s confusion. “We’re constantly monitoring her mental state. When she’s on Fraxinus, her stress levels are dramatically higher than when she’s at school.”

“Th-they are?”

“…Mm-hmm. And she doesn’t seem to like the testing twice a day much, either. Her stress levels are still within acceptable limits, but I can’t really say it would be smart to let her be like this. And so.…” She put a finger to her chin. “Her test results have stabilized, and it’s getting to be time we moved her living quarters off Fraxinus.”

“Uh-huh… Is that right?”

“…Mm-hmm. All of which is to say that until we can build a special housing unit for Spirits, Tohka will be living here.”

“Wait. Hang on.” He pressed a hand to his forehead.

“…Something wrong?”

“Wh-why does it have to be our house…?” he asked.

“…Well, to put it simply, Tohka’s most stable when she’s with you,” Reine told him.

“Huh…?” He gaped at her.

“…Basically, you’re the only human being to have earned her trust so far. Kotori and I see her relatively frequently, but she still doesn’t trust us. We want to try and see how Tohka does in a place where she’s a bit more stable.”

“…Ngh…,” Shido groaned, sweat beading on his forehead.

When she said it like that, he couldn’t help but feel that this was the only sensible move. And—well, the fact that Tohka trusted him… He didn’t exactly hate that, either.

He shook his head slightly, as if to get his thoughts back on track. He couldn’t consent to this situation so easily.

“So? What’s the other reason?” He pressed Reine for more information.

“…Mm-hmm. That one’s much simpler… It’s for your training, Shin.”

He gasped. Tohka had said the same thing before he’d changed out of his wet clothes. Training. He didn’t have particularly good memories associated with that word.

“Right, Tohka said that, too… But what’s the use in training now?”

“…Hmm? And why wouldn’t you continue?”

“Why? …I mean, her Spirit power’s been sealed away…”

Reine shook—or rather wobbled—her head from side to side. “Who said Tohka was the only one?”

“Huh? So… What do you…?”

“…I’m sure you can piece it together,” she said. “Tohka’s not the only catastrophic creature causing spacequakes—code name Spirit. At the present stage, several others have been confirmed.”

“Wha—?!” He felt something tug at his heart.

Tohka wasn’t the only Spirit?

A feeling that was impossible to describe—nerves or maybe fear—roiled in the pit of his stomach and radiated outward through his body, making his fingers and toes tremble.

Reine paid no mind to the frozen Shido. “…Shin. We want you to continue talking to the Spirits. So you have to train.”

“…Y-you have to be kidding—,” he cried out, planting his hands on his knees.

“Hmm?” Kotori said, breaking her silence. At some point, the ribbons that tied her hair up into two bundles had changed from white to black.

“—” He’d seen this before. She was in commander mode now.

“You don’t want to train, Shido?” she asked, seeming very grown-up all of a sudden, in contrast to her childish attitude earlier. “You’re saying you don’t want to date the Spirits and make them fall for you anymore?”

Right. The method of peacefully neutralizing the Spirits espoused by Ratatoskr sounded idiotic when put into words: have Shido get friendly with the Spirits and seal their powers with his body.

“O-of course not!” he cried.

“Huh.” Kotori leaned back slightly and lifted her chin. “So then, that’s the end of that, I guess.”

“Uh…?”

“We sit back and watch quietly as the world is ripped apart by spacequakes. Or we patiently wait for a miracle and for the Spirits to be killed by the AST… It’ll be one or the other, I suppose.”

“…Urp.”

At this, he was at a loss for words. It wasn’t that he had forgotten. But his heart ached when she spoke that truth out loud.

The Spirits existed in an alternate space that they referred to as a parallel world and only occasionally appeared in this world. But when they did, they warped the walls of space-time, bringing about the phenomenon known as a spacequake. Although the quakes differed in scale, areas where the Spirits manifested were completely obliterated, like the aftermath of a massive explosion. The Self-Defense Forces Anti-Spirit Team—the AST—viewed these Spirits as extremely dangerous and attempted to exterminate them with firepower.

“There’s one person in this world with the unique ability to seal a Spirit’s power,” Kotori said. “And you’re saying you don’t want to do it. So that’s the end of the discussion then, isn’t it?”

“…Wh-what…the…?!” He groaned in agony. Without his knowledge, he’d been saddled with such a heavy responsibility, and the weight of it was making his shoulders hurt. To get to the heart of that, he needed to confirm a few things himself. “Kotori.”

“What is it?” she replied leisurely, perhaps having guessed more or less what his question would be.

“Tell me: What exactly is Ratatoskr? When did you join this group? And what is this power of mine?”

This was what he’d been wanting to ask this entire time, questions he hadn’t been able to get answers to, given Kotori’s long absence from the house.

She sighed, pulled one of her beloved Chupa Chups from her pocket, unwrapped it, and popped it into her mouth. “Right. This is the perfect opportunity. I guess I could give you the overview.” She leaned back against the large cushion behind her. “Ratatoskr was formed by a group of sympathizers. Well, if I had to say, it’s like a kind of nature conservancy. Of course, its existence is not made public.”

“Nature conservancy… Huh.” Although this didn’t quite click for him, he was reluctant to interrupt her. He waited for her to continue.

“Yes. And as to the reason for the formation of Ratatoskr, the biggest objective, well, that’s to protect the Spirits and give them a happy life. Although some of the Rounds, the top executive group, have the perverted desire to make the Spirits’ powers their own and do all kinds of things with it.”

“Huh…? Your objective isn’t to avoid the spacequakes?”

“Oh, well, of course, there’s that, too.” She waved a dismissive hand. “But that’s secondary at best. If that was our only goal, we’d be no different from the AST.”

“Ngh, well, I guess. So then…how and when did you end up commanding this organization? I had no idea.” He hadn’t intended to accuse her of hiding things, but her keeping such an important secret, something that was life-and-death in the worst-case scenario, annoyed him a little as the older brother.

Perhaps guessing at this mental state of his, Kotori sniffed at him. “I was appointed the commander of Ratatoskr’s combat unit around five years ago.”

“Five years ago, huh…? Wait. What?!” Shido did some mental math and jerked his head up. “D-don’t be ridiculous. Five years ago…you were still only eight!”

No matter how unusual the organization was, it was not a sane state of affairs to put a third-grade girl in the position of commanding it.

“Well, for a few years, it was more like training,” she replied. “It’s just recently that I’ve actually taken command.”

“N-no, that’s not the issue here. What is a little girl—?”

“Well, what can I say? Ratatoskr recognized my superior intellect.”

“This makes no sense!” he cried.

“Say what you want, but it won’t change the facts. Be a good boy and believe what your little sister tells you. Do you think arguing makes you look smart or something?” Her words and manner were almost entirely different from the cute Kotori he knew.

Sweat ran down his cheeks. “Is this dual personality of yours also Ratatoskr’s fault?”

She snorted. “Rude and simplistic. Think a little harder before you speak. First of all, this—”

“This?”

“…” She looked up at him with a somehow mysterious expression before shaking her head as if to brush off his outburst. “None of that matters. An incident five years ago became a turning point for the organization.”

“Hey, don’t dodge the—”

Kotori cut him off by snapping her Chupa Chups stick at him. “We discovered a boy who could seal the Spirit powers with a kiss. This led to Ratatoskr shifting to a policy of actively protecting the Spirits.”

“Wh—?” He furrowed his brow, dumbfounded. “Y-you’re saying that was…me?”

“Yes.” She nodded and put her lollipop back into her mouth.

“H-hang on a second here.” His head was in complete chaos. He’d been given too much information at once, and he couldn’t process it all. “Why do I have this power in the first place?”

“Dunno.” She shrugged.

“Uh? W-wait, what? You don’t get to feign innocence after telling me all that.”

“I’m not feigning anything. I seriously don’t know. You can take the power from a Spirit with a kiss and seal it in a stable state in your own body. All we know is that you’ve got this ability. At least, I don’t know why you have a power like that.”

“S-so then, how did you find out I could do this?! Five years ago! What happened exactly?!” He pulled his hair frantically with both hands.

“…” She glanced down, averting her eyes, her face colored with unexpected grief. It housed an expression steeped in deep emotion. As if recalling some painful memory. As if regretting an irreversible mistake.

His heart flipped over in his chest. “K-Kotori…?”

“Uh. Um.” She jumped slightly. “Right, they checked you out with, uh, Ratatoskr’s measurement device. And that’s how they found out. It was the same for me,” she told him in an evasive manner, far from the decisiveness of her commander mode.

For some reason, he felt like he couldn’t press her any further.

“A-anyway.” She cleared her throat and snapped out a finger at him. “What you need to know right now is that you have the power to do something about the Spirits. That’s it! So I’m going to need you to make a choice. About whether you’ll seduce the Spirits for us or not.”

Shido pursed his lips. It was such a mean-spirited question. He was the only one who could seal the Spirit’s powers. If he didn’t do it, Spirits—creatures in the same situation as Tohka, who he’d been so desperate to save—would be assaulted by the AST. Even though they weren’t necessarily intending to destroy the world, they were unilaterally categorized as a catastrophe and targeted for annihilation. Not to mention the issue of the spacequakes. Unless the Spirit’s power was sealed, they could be looking at another massive disaster on the level of the Great Eurasian Spacequake at some point.

He let out a long sigh and picked at his hair. “Let me think about it a bit.”

“Well, that’ll be fine for now.” Kotori snorted before turning her gaze on Reine sitting next to her. “Okay then, Reine. Make the preparations.”

“…Mm, leave everything to me,” Reine said, her head bobbing from side to side. “…It’s basically ready.”

Kotori whistled. “Fast as ever.”

“…Preparations? For what?” Shido got a bad feeling as he listened to their disquieting conversation.

“What? Tohka’s room, of course,” Kotori replied as if it were the most obvious thing in the world. “She’ll be using the guest room upstairs.”

“H-hang on a sec! I said I’d think it over!”

“Mm-hmm. So don’t pay us any mind. You go and think on it long and hard.”

“How am I supposed to do that?!” he shouted.

“So loud.” She plugged her ears, looking exasperated. “Either way, our only choice is to have Tohka stay here until the special housing unit’s ready. And it’ll be too late to start training once you’ve made your decision.”

“You say that, but…I don’t know how an adolescent boy and girl can live under the same roof!” he cried, blushing beet red.

She laughed. “If we thought you were capable of having some passionate love affair, we wouldn’t have had to put in all this work.”

“Hngh…!” It made him sad that he couldn’t argue that. “That’s still no excuse…!”

He heard a door opening behind him—the entrance to Kotori’s bedroom. His shoulders jumped up as he looked back.

Tohka was giving him an uneasy look from the hallway. He didn’t know how long she’d been standing there.

“…Shido… Am I not allowed to be here…?”

“…Urp.”

He felt something catch in his throat at the sight of her sad eyes, the ends of her eyebrows tugged down. If there was a person alive who could say no in the face of this, he would like to meet them. He sighed long and hard.

“…F-fine…!”

“So how exactly will I be training? What on earth do you intend to make me do?” he asked Kotori, who was sitting on the living room sofa, about three hours after he’d been basically strong-armed into nodding his head in agreement.

It was just the two of them. Reine had gone back to Fraxinus after the earlier discussion, and Tohka had headed for the guest room after supper. Her things from her room on Fraxinus had arrived, so he assumed she was unpacking.

“Nothing in particular,” Kotori said, satisfying her post-dinner cravings (with a Chupa Chups, naturally—not a cigarette), black ribbons tying up her hair.

“Huh…? What’s that supposed to mean? You wouldn’t shut up about training before.”

“Mm-hmm. To be more precise, your task is to simply live your life, I suppose.”

“Excuse me?”

“The objective is for you to talk to girls without getting flustered, since you’ll be going on dates with many Spirits going forward.”

“…Ohhh, now that you mention it, you did say that.” He remembered what he’d been forced to do last month with the dating sim and training to become a pickup artist, and his cheeks stiffened.

“This time, you’ll get hands-on training with a girl living with you. Basically, I want you to remain calm and act like a gentleman even if you are suddenly thrust into temptation.”

“…Uh-huh.”

“So during the time you’re living with Tohka, all you have to do is not panic or get flustered—no matter what kind of eyebrow-raising thing happens.”

“Wh-what the…?” he groaned, a massive crease forming between his eyebrows. A question popped up in the back of his mind. “…But, like, why do I have to seduce the Spirits to begin with? I can seal their powers with a kiss, right? So then I catch them off guard and—”

“Oh my. So you like it rough, Shido? Be careful you don’t wind up in the morning papers.”

“As if!” he shouted.

“It won’t work.” She shrugged, exasperated. “Their powers won’t be completely sealed unless they open their hearts to you.”

“Th-they won’t…?”

“Nope.” She shook her head. “I’m not telling you to make them head over heels for you, but it’ll be pretty rough if they don’t trust you enough not to refuse a kiss at the very least. That’s why Reine monitors the Spirit’s mood and your affection rating so closely.”

“R-right…” The more he heard about his power, the less he understood it. “Hmm?” He leaned his head to one side.

Kotori was speaking in a whisper. “Right. Understood. Mm… Bye…”

When he looked very closely, he could see a small earpiece in her right ear.

“Kotori? Who are you talking to?”

“Ohhh, it’s nothing. Don’t worry about it. So anyway, Shido.” She bounced up off the sofa. “I need to go to the bathroom.”

“Huh? Then go.”

“The lightbulb was burned out when I checked. Could you maybe change it first?”

“Sure… I guess I could.” Somewhat suspicious, he pulled a spare lightbulb out of the cupboard and headed to the bathroom with it and a stool to stand on. He set the stool down on the floor and opened the door. And froze in place.

“…?!”

But that was only natural. Because someone was already in the bathroom.

“Wh—? Shido?!” Tohka was sitting there with her panties pulled down to her knees.

“T—! T-T-T-T-T-T-T-Tohka…?! Why are you in here—?” he squeaked, feeling his heart thudding in his chest.

Weird. The door hadn’t been locked. Plus, the light that Kotori had said was burned out was shining brightly, but the switch outside was in the off position. It was easy for someone to walk in by accident.

“I—I could ask you the same thing! Close the door already!” Cheeks flushing, she yanked down the hem of her sweatshirt while she grabbed the roll of toilet paper from the wall and threw it at his face.

“Gah…?!” The toilet paper might have been soft, but it did make its own impact when thrown with force. A yelp slipped out of his throat, and he fell down backward on the spot.

Tumble, tumble, tumble. After its kamikaze attack on Shido’s nose, the toilet paper drew a white line down the hallway.

“Wh-what is going on…?” he groaned, staring at the ceiling.

Kotori appeared above him suddenly. “Pathetic. I just told you not to panic and get all flustered.” She was standing in an imposing stance with her legs apart right by his head, so her underwear was on full display. But even Shido was not depraved enough to get worked up at the sight of his little sister’s panties.

“…Kotori. You did this,” he snarled.

She flicked up the stick of her lollipop as the corner of her mouth tugged upward.

So she had calculated this when Tohka went into the bathroom and launched a surprise attack. She’d even gone so far as to do a little work on the lock and the light switch.

“Your condition is always being monitored on Fraxinus, Shido. The crew and the AI there make detailed decisions about the success or failure of your response. Naturally, you failed now,” Kotori said and showed him what she’d been keeping hidden behind her back.

“Huh…?”

It was a small radio. She turned it on and fine-tuned the bandwidth.

“Fraud rules the world. Corruption consumes its adults. We must resist following their path. Put our power on display—a devastating wonder. Don’t halt your treading feet from marching toward the future…”

A voice dispassionately recited a poem. He’d heard this somewhere before. Right. He’d written it himself when he was in junior high.

“Ah! Aaaaaaaaaaaaaaaaah?!” Shido cried out so loudly it threatened to crush his vocal cords, and he reached to turn off the power.

“No use in that. I mean, it’s already on the air.”

“Wha—?!” His face turned bright red.

“A variation on your previous penalties. I can’t have you going along all happy-go-lucky just because this is a practice round,” she told him. “Anyway, relax. As long as you don’t fail at everything, the author’s name won’t be released.”

“So you’re basically saying that it will be if I do fail!” he yelped.

“I’m telling you to get used to girls before that happens. I’m not saying you can’t be excited. As long as you respond calmly however nervous you are, you’ll be in the clear.”

“Th-that’s impossible!” The video game was one thing, but Shido had no previous exposure to this in real life. He had no immunity. “A-and, like, didn’t you say we couldn’t upset Tohka’s mental state…?!”

“Oh, we’re all good there,” Kotori reassured him. “There are all kinds of emotional upsets. The possibility of the Spirit’s power flowing back with this sort of thing is low.”

“B-but still…”

He heard a creaking sound from behind. Tohka had opened the door slightly and was peeking out, her face perfectly red.

“T-Tohka…?” He averted his eyes slightly. It might have all been Kotori’s fault, but it was still hard for him to look at Tohka when she seemed all embarrassed. “S-sorry… I didn’t do it on purpose. Forgive me…”

“I forgive you… So, um.” She pointed at the white line drawn in the hallway, her cheeks flushing even more deeply. “F-fetch the roll for me.”

“Oh…” Now that he was thinking about it, he was pretty sure no one had put out an extra roll of toilet paper. He got the roll that had escaped down the hall, wound it back up, and handed it to Tohka.

“Shido. The bath’s ready. You go on ahead,” Kotori said casually to a tense Shido right when the clock hit eight PM.

“The bath, huh?” he replied, wondering exactly what card she was planning to play now, and looked around the living room.

Kotori was lying down, clutching a game console controller connected to the TV. Tohka was not there, of course. She had vanished earlier when he stepped out for a few minutes. Kotori said she’d gone to her room to get something, but he was not so naive as to believe that at this stage of the game.

“Nah, I can go later,” he said with composure. “Why don’t you go first?”

“…” A twitch.

The fact that her toes, which had been bouncing happily in time with the video game music, stopped for an instant did not escape his notice.

“I’ll pass. I’m at a good part right now,” she said in a transparent lie, her eyes still glued to the screen.

Shido was sure of it. This was a trap. Kotori had no doubt sent Tohka to the bath while he’d been out of the room, in another surprise attack like the scene in the bathroom before, so she could delight in watching him squirm again. There was no way that the clever Commander Kotori Itsuka would overlook the opportunity for that classic of all classics, the bath scene mishap.

However, he’d already run into Tohka in the changing room when he came home that day. Kotori was too smart to go putting her train on the same track twice.

“Come on now, don’t be like that.” Shrugging slightly, he readied the special attack he’d been saving for just such a moment. “You can use the fancy bath salts today.”

“…?!” Kotori’s pigtails jumped up and stood on end (metaphorically speaking).

When bath salts were used in the Itsuka house, the first person to take a bath was given the task of putting the salts in so that everyone could enjoy the healing powers of its bubbles. And Kotori had never missed an opportunity to take on that role.

“…”

“…”

A quiet moment after supper. If someone who knew nothing of the situation were to see them now, they might have looked the very picture of a harmonious family. But an intense psychological war (or something like that) was playing out below the surface.

So what’s your move, Kotori? In his mind, Shido saw the somewhat surreal sight of the impregnable Fort Kotori under violent attack by bath bombs.

Her toes were twitching, as though her soul were on fire. Certain of his victory, he pulled the corners of his mouth up into a grin.

Bwa-ha-ha-ha-ha! Don’t underestimate me, girl. Shido Itsuka has not been your brother all these years without picking up a trick or two!

However…

“H-huh,” she said after a while, her voice shaking. “Oh yeah…? Cool… Shido, you. Go on. First.”

“Wh—?” He frowned at this unexpected response. She might have been in commander mode, but she shouldn’t have been able to resist the magic of the fizzy bubbles of bath salts!

He looked at her very, very closely and saw that she was shaking, and she was strenuously massaging the palm of her hand.

“…”

Her entire being was clearly in a battle against the urge to leap up and run to the bathroom.

“Sorry I took so long, Kotori. Now, time to fight!”

Shido heard a voice from behind and looked back with a start.

Tohka was standing there with a blanket in her hand.

“Tohka?!”

“Mm… What’s wrong, Shido? You got a weird look on your face.”

“O-oh, nothing,” he stammered. “Where’d you go?”

“Mm. Kotori asked me to play a game with her, but I was feeling a little cold. So I was looking in my boxes for something I could put on my lap.”

“Wh—?” He reeled at this revelation, the world turning inside out in front of his eyes. So Kotori was telling the truth? Was he simply punching at shadows here…?!

Overcome with a sense of defeat for some reason, he staggered out of the living room. “I’m going to take a bath.”

“What’s wrong with Shido?” Tohka asked.

“…No idea.”

With the girls’ voices behind him, he went out into the hallway, grabbed a change of clothes and a towel, and then closed the door to the changing room.

“…” He paused for a second and then knocked on the door to the bathroom before opening it, just in case.

“Huh. So it really isn’t a trap.” He let out a sigh of relief as he quickly undressed in the changing room and stepped into the bathroom. He reached out for the bath salts, but surprisingly, he felt kind of bad for Kotori. He decided he’d let her use the special salts tomorrow and contented himself with throwing in the regular non-bubbly kind.

He quickly washed himself in the shower area next to the tub and then sank into the milky-white water.

“Haah…” His long sigh bounced off the walls of the bathroom, echoing. “I’m totally wiped out today.”

He sighed again as he splashed water on his shoulders. He could feel the exhaustion melting out of every pore on his body and slowly closed his eyes, drifting away in the comfortable warmth of the tub.

“Hmm, hmm-hmm-hmm-hmm, hmm-hmmm. ”

Abruptly, he heard a nasal humming. “Huh…? What’s that…?”

He opened drowsy eyes and turned his face in the direction of the song. And then he froze, blood curdling as he cursed his own carelessness.

“…!”

And this was to be expected. On the other side of the clouded glass that separated the bathroom from the changing room, he could see the hazy figure of a girl with black hair.

“S-so this was your objective, Kotori!!” he groaned, pressing a hand to his heart.

A surprise attack with a feint, leading him to suspect she was playing the same trick twice. But she hadn’t been luring Shido to Tohka—just the opposite. It was a simple but effective scheme. He had nowhere to run.

“You planned this, didn’t you…?!”

He suddenly had a vision of Kotori in sunglasses, a bold grin on her face as she raised a whiskey glass to him, saying, “Can’t beat me, boy.”

Now was not the time for a leisurely analysis of the situation.

Tohka had undressed and now had a hand on the bathroom door.

Bewildered, he decided he couldn’t let her find him in here, so he sank into the water and pulled the tub lid closed above him.

As if on cue, he heard the door opening. This was followed by the clattering of the bath lid being pulled back again.

“Hup!” Without so much as a glance at the tub, Tohka leaped into the water.

Water sprayed, and he suddenly felt something soft near his stomach.

“Mm?” And here, at last, Tohka sensed that something was askew.

He popped his face up over the surface of the milky-white water, forced to say hello since his lungs had run out of air. “H-hey.”

“…”

They stared at each other for a few seconds.

“Nnnnnnnnnnnnnn…?!” Tohka’s face turned tomato red.

“C-calm down…!” he yelped.

“Idiot! St-stay down!” She grabbed his head and pushed it back down into the tub.

“…! …!”

Not having been able to get a real breath, he did not have sufficient oxygen in his lungs for another trip into the water. They grappled briefly in the small tub before Shido passed out and bobbed to the surface.

“Failed again!” He half heard Kotori above his head, and the radio made a lengthy speech, but he couldn’t respond to either.

“I…really took a…hit there.”

After regaining consciousness, Shido pulled himself out of the bath before heading into the kitchen to wash the dishes piled up in the sink. By the time he finally finished prepping the meals for tomorrow and staggered back to his own bedroom, the hands of the clock were pointing to eleven.

Good girls like Tohka and Kotori were already asleep in their own rooms, and while it was still early for a healthy teenage boy, he was exceptionally exhausted. He felt like Kotori had to be out of ideas for today at least, so he dived into his bed and quickly fell asleep.

“…ri. Kotori, wake up. It’s time.”

“Unh… Nnn.” Kotori twitched at the voice in her ear in the middle of the night. Everyone was fast asleep.

Thirteen-year-old Kotori Itsuka’s sleep was not so light as to be woken by something like that. She twisted on the bed and rolled over to pull the blanket around her before her breaths slowed once more into the gentle inhale-exhale of sleep.

“…Kotori. Kotori. You have to wake up.”

“Mmm.” She rubbed her half-open eyes and sat up slowly. “Whaaat is it…? Big Broooo.”

“…It’s not Shin. It’s me, Reine.”

“Reineeee?” She let out a big yawn. “What’s up? It’s late.” She patted her pillow and groped around for her cell phone. She made the screen light up and looked at the time. Three thirty AM. A time when all children—good and bad—were lost in dreamland.

“…Everything’s ready. Just need you to give the order.”

“Oh.” She opened her mouth. “Mm, right… I asked you to wake me up.” Head bobbing like Reine’s usually did, she patted her pillow once more and picked up the bite-size lollipop that had been placed there before roughly tearing the wrapper off and popping the candy into her mouth.

“—!” She shuddered fiercely. It felt like something was exploding on her tongue, and a sharp scent wafted up into her nostrils.

Yes. This was no ordinary Chupa Chups. This was a super-refreshing, super-menthol lollipop, her secret weapon she sucked on only when she wanted to hold back sleep.

She took her black ribbons in hand and tied her hair up into her usual pigtails. “Aah. I’m awake now. Sorry, Reine.”

“…No problem. So to get right to it, my report. Shin’s entered deep sleep.”

“Yeah? What about the team?”

“…On standby, just as you asked. Ready to go at any time.”

“Good,” she said and left her room on quiet feet, then went down the stairs and made her way to the front door. And then with a clack, she unlocked it.

Several men wearing black combat clothing and balaclavas were waiting there, looking like an American special forces unit.

“Target’s upstairs. Get to it.”

“Roger.”

The men crept soundlessly into the Itsuka house.

“Mm… Unnnh.” Shido stretched out on his bed.

His eyes took in the morning sun pouring in the window, while his ears caught the chirping of birds.

“Mm…morning already?” He yawned and turned over, blinking rapidly. He felt something soft touch his cheek, and he frowned. “Uh…? What’s this…?”

To find the source of the softness, he slowly moved a hand up to his face to feel it.

“Mm…!”

He heard a somehow adorable voice above his head.

“…” He stopped breathing for a moment, his thoughts racing.

Shido glanced around and found a thin fleece fabric in front of him. When he looked up at the ceiling, the light fixture there was not the one he was used to seeing.

This was…not his room. From the fixtures, he guessed that it was the upstairs guest room, a room he generally had no reason to enter.

“Which. Means…” He slowly turned his face upward.

“…Mm?”

Just as he expected, he found Tohka’s beautiful face there.

It seemed she had also just woken up. Their eyes met. And a brief silence followed.

“…”

“…”

“Eeeek…!” Tohka squealed.

“Wh—?” Shido yelped.

They both leaped up, one to the head of the bed and one to the foot, as if the bell for the start of the match had just sounded.

“Wh-what are you doing, Shido?!” she shrieked. “Why are you in my bed?!”

“I—I don’t know!” he shouted, in a total and inexplicable frenzy. “Wh-wh-wh-wh-wh-why am I here?!”

“That’s what I’m asking!”

“Riiiiiiiight?!” Shido screamed back.

“Aaaand batter out.” Kotori sighed in the doorway. “You have to keep your cool, Shido.”

“…Kotori?!” he yelled. “Y-you didn’t—? You did this?!”

“Whatever do you mean? You must have been unable to contain your youthful libido and climbed into Tohka’s bed. You can quit with the weak excuses.” She shrugged through her brazen lies, a slight smile on her lips.

“Wha—?” Tohka’s face flushed scarlet, and she pulled the blanket up to cover her chest.

“I-I’m innocent!” he cried.

Kotori paid him no mind and instead began to fiddle with the phone she pulled out of a pocket. And it was his phone, for some reason.

“Hey—! That’s my phone! What are you doing?”

“Huh? Ohhh.” She turned the screen toward him. An e-mail was displayed there, the name of Shido’s best friend, Hiroto Tonomachi, in the address field.

He gasped. Because the body of the message read, This radio program is amazing. Give it a listen. It’s mind-blowing. The kind of thing that’ll change your life forever. Followed by a link to a website.

“Huh…? Wh-where’s that link go…?”

“Oh, they started streaming that program from yesterday,” she told him casually. “Now anyone can listen to your tour de force masterpiece whenever they want, as long as they have access to the Internet.”

“Wha—?!” Fear opened his eyes wide, and he reached out his hand. “D-don’t—”

“Go!” She pushed the send button before he could finish speaking.

“Aaaaaaaaaaah?!” He yanked his phone away from her and desperately pressed the cancel button. But it was too late. The conveniences of modern civilization had delivered this ruinous information to his best friend at the speed of light. “Wh-what are you doing…?!”

“Delivering your penalty. I can’t have you freaking out just because you touched Tohka’s boob.”

“Wh-what did you say…?” He cocked his head to one side. Something wasn’t quite clicking here.

Now that she mentioned it, he did have a hazy memory of touching something extreeeeemely soft right before his brain woke up fully. Ever so timidly, he looked toward Tohka, and her eyes were also round as saucers.

And then she started to pat at her own body, as if remembering some forgotten sensation. When she got to her chest, she froze. Her face turned bright red, with such force and saturation that it almost sent up smoke.

“Unh… Aaaaaaaaaaaaah!” She let out a fierce shriek and started throwing everything she could get her hands on.

“Whoa…! C-calm down, Tohka!” Shido tried to make a quick exit, somehow dodging the barrage of objects, but when he placed a hand on the doorknob, he was hit with a red cow statue and knocked unconscious.