Tatsuya, who was watching the morning news broadcasts while eating breakfast, realized he was nodding off unconsciously and hastily stopped his neck from moving. Fortunately, Miyuki’s eyes had been on the television screen, too, so it didn’t seem like she’d noticed.

“Could it have been a device malfunction? It doesn’t seem as though it ran afoul of any poor weather, like storms or thick fog.”

Miyuki was currently preoccupied with confusion about the news that a small American navy vessel had been drifting in Japan’s offshore territory around Chiba Prefecture’s bay.

“I can’t imagine their instruments all failed at the same time. Maybe the issue was with their power source,” he suggested. “After all, with how far automation has come in this day and age, a simple human error wouldn’t have caused them to lose their steering.”

His sister nodded, not doubting his words for a moment. When he looked over her innocent (?) figure, he felt like it was cleansing him, right down to his corrupt core—but of course, he knew that was no more than an illusion.

Even still…

This response was too fast, even assuming our aunt issued a direct order.

Considering the time at which the drifting vessel had been secured, it would mean that after Tatsuya contacted Hayama, she’d finished sorting out the aftermath of the attack Tatsuya had faced within not a half day but half even of that.

The Yotsuba’s operative team might have been talented, but it was impossibly fast if they’d had to go from step one.

Which meant…

Their forces were already in position by the time I contacted her.

He didn’t know what her intention behind that was. The timing might simply have been coincidental, or she may have been trying to interfere as little as possible.

It was also possible she had waited until Tatsuya came to them, head bowed.

Even if they did, I still don’t feel I owe them anything.

It didn’t matter what was going on behind the scenes—if things turned out better as a result, that was enough for Tatsuya.

Miyuki nodded when her brother mentioned a power source–related issue, then quietly considered him.

He didn’t seem to have any suspicions.

It pained her to deceive him like this, but even she occasionally had things she didn’t want him to know.

She wanted him to believe that she was ignorant of the situation.

Miyuki brought their dishes into the kitchen, then left the rest of the work to their HAR (home automation robots) and went upstairs to the second floor to change into her uniform.

With her mirror in front of her, she breathed a little sigh.

She’d known about that news without needing to see it on TV. It had been after Tatsuya had left for his usual morning training.

She’d received a phone call from Maya.

Maya’s news was that they’d eliminated all the USNA military forces that had threatened Tatsuya.

Miyuki didn’t know exactly who in the Yotsuba family had done it, so Maya had been the only one Miyuki could show her gratitude to. She knew it was a method of controlling her, but this time, she actually felt thankful. Including for how Maya had kept it a secret from Tatsuya that Miyuki had asked for Maya’s help, even when both she and her brother were planning to betray the woman.

It was a dirty move… If Brother knew the truth, I’m sure he would stop liking me…

Miyuki didn’t want Tatsuya to think she was a stupid girl.

But at the same time, she didn’t want him to think she was too clever, either.

From her heart, Miyuki never wanted to be a burden for him.

And at the same time, she absolutely wanted to avoid making him think he didn’t need a little sister anymore.

Once her brother decided she could do her job independently as leader of the Yotsuba…he might leave her.

And even if he didn’t, he might put distance between them.

That possibility was a nightmare that tortured her.

Miyuki and Tatsuya were siblings related by blood. Once they grew up, it was natural she’d leave him—and natural he’d leave her.

And she knew she’d eventually have to get married, too.

She knew she’d have to take a husband who wasn’t her brother.

Miyuki didn’t wish for it, but society, this nation called Japan, wouldn’t allow it. Not as long as she was a talented magician with highly desirable magic genes to pass on.

And that wasn’t too far in the future, either—it was close at hand.

Currently, magicians were expected to marry early. Female ones in particular were expected to marry quickly and bear children even faster. This was because for each new generation of magicians, their innate abilities tended to improve. Scientists called it “magic adapting to genes.” There wasn’t much of a difference in generations for top-class levels, but when comparing average abilities, it was true that the current generation’s was higher compared to their fathers’ generation, which was in turn higher compared to their grandfathers’. Eventually they would probably reach equilibrium, but at the moment, the birth of a new generation was very much anticipated.

To the point where female students attending the National Magic University commonly took time off from school to raise children.

The same expectations didn’t apply to engineered magicians whose life spans were unstable, but even they were in their second generation. When it came to the third generation, everyone was looking at them as though they had a duty to give birth as soon as possible. The Shiba siblings’ mother, who had married late, and their aunt, who insisted on remaining single, were rare exceptions. And even those exceptions wouldn’t have been allowed if not for physical reasons exacerbating the issue.

As it was, Miyuki was a perfectly healthy specimen and so didn’t meet those criteria.

In fact, she possessed particularly excellent factors that made her a hopeful for the next leader of the Yotsuba.

In truth, she didn’t want any other man besides her brother to embrace her. That was how she truly felt. In fact, to be completely honest, she didn’t want any man besides her brother even touching her at all.

It wasn’t a morbid distaste for it, like a physiological rejection, so she was fine with things like dancing. But to bluntly spell out her feelings, she was only okay with Tatsuya touching her. It was only okay for Tatsuya to do with her as he pleased.

She looked at herself in her underwear in the mirror. As she did, she thought to herself. These fingers, this hair, these lips, this chest, the secret places she wouldn’t show to anyone—if it was Tatsuya, he could touch her. If it was Tatsuya, she wouldn’t care what he did to her.

Both my body and mind, everything about me, belongs to Brother

These were her true sentiments, a prayerlike wish from the bottom of her heart.

But she knew those feelings would never be fulfilled.

So this is what she thought instead:

I’m all right being a bad sister… No, I’d much rather he think I was a bad sister. If that’s what it will take for him to stay at my side…

Meanwhile, she decided that she would do her best to secure Tatsuya’s affections, whether that would be to keep herself from being seen as evil or boring.

That was Miyuki’s current dilemma.

Entering classroom 1-E, Tatsuya sensed a strange mood in the air. He scanned the room with his eyes and quickly found the reason.

The twenty-five seats in their class were arranged in alternating male-female columns in alphabetical order. In front of Tatsuya was Leo, to his left side was Mizuki—and the source of the dark clouds was in a window seat another row over.

Erika was staring out the window glumly. She almost looked like an aura of distaste was exuding from her body.

Well…I can’t blame her. Tatsuya had a good idea why she was unhappy. Considering the commitment he’d seen from her in the summer, he was confident the particulars of last night were probably hard to accept.

As Tatsuya simply gave Erika a glance and then took his seat, a voice next to him asked, “Oh, Tatsuya… What do you think happened to her?”

Mizuki may have been addressing him, but half her mind seemed occupied with Erika. But that wasn’t the whole of it—she’d obviously guessed, quite sharply, that Tatsuya knew what was going on.

The next thing he realized, Mikihiko and even Leo were giving him the same look.

But there were things he couldn’t give them even if they asked. At least, there was no way he could tell them that Lina had defeated Erika’s brother last night.

“I wonder what it could be?”

In the end, all Tatsuya could do was feign ignorance.

They didn’t press the issue, a good virtue as friends. Even if it was for different reasons—Mizuki because that simply wasn’t her personality and Mikihiko and Leo because they personally knew everyone had things they didn’t want to talk about.

But even that couldn’t defeat the uncomfortable mood swirling in their midst.

The awkward atmosphere persisted, too. For lunch, the five classmates were all apart for the first time in a while—“classmates” specifically, rather than “friends,” because Miyuki and Honoka were acting the same as always.

The change came only after school let out.

Like he’d told his sister last night, Tatsuya immediately went to negotiate with the robot club (there was some monkey business involved) and personally rented Pixie from them, since they were her temporary owners.

The point was to question her, not to play with her, but the robot club’s garage wasn’t fit for such a thing. Nevertheless, leading her around the school in her outfit would have stood out too much. He wasn’t in the mood for others casting doubts on him (namely on his hobbies), and considering his objective, her standing out at all would have been an issue.

Due to the circumstances, he first had Pixie change into a girl’s school uniform. He borrowed the uniform from the art club through Mizuki; it was a model they used for portraits. Pixie’s frame was different from a human skeleton, so he was worried whether she’d be able to change into it. But the 3H’s body was more flexible than he’d thought, and she had no problem removing her maid dress and putting on the uniform. There were some unnatural lines around her lower body, but he’d known that would happen, and so he’d borrowed a uniform one size too big, making it less conspicuous. She’d look like a regular student to a mere passerby in the hallway—and just for the record, Tatsuya felt nothing watching a robot change clothes.

With all that done, Tatsuya brought Pixie into an empty classroom in the lab building and began his questioning.

He quickly got used to how odd it felt to hear her active telepathy echoing in his brain. But he really couldn’t get used to Pixie’s inorganic optical sensors (her eyes) and the passion there. Feeling uncomfortable in a way he never had before, Tatsuya continued his inquiry.

He asked about the vampire incidents. Especially the strangeness of the victims having a large amount of blood loss while not having any notable wounds on their bodies. He asked about the mechanism therein and about their motives. It had been weighing on Tatsuya’s mind ever since he’d first learned of the incidents.

“Were the parasites responsible for the victims’ blood loss?”

“Yes.”

“Why did you need blood from a living person?”

“Blood loss was not our intent. It was a side effect of mistaken propagation.”

“Explain in more detail, please.”

“Our propagation process starts by cutting off part of ourselves and sending it into a recipient—a human body we perceive as capable of hosting us. The separate body spreads through blood vessels while absorbing psions and psycheons in the bloodstream. It permeates the recipient’s physical body by exchanging itself for their blood.”

“Wait… Exchange itself for their blood? You’re bodies of information—you don’t have mass. Where does the exchanged blood matter go?”

“It is used to modify their body during assimilation. Should assimilation fail, the separate body is expelled from the recipient’s body as vitality.”

“I see, so that’s how it works… Continue.”

“Should permeation of the body succeed, we can control its information body—its ethereal body.”

“An interplay between physical bodies and information bodies? The same basic tenet as magic.”

“The ethereal body is also a route to the mental body. If we can access the recipient’s mental body through their ethereal body and merge with it, our propagation succeeds. Unfortunately, however, we have had no successes.”

“Why not?”

“Unknown. I wanted to know this as well. For some reason, the idea alone remains within me.”

“…How many of your group are in this country?”

“Immediately prior to inhabiting this body, there were seven—eight, including myself.”

“Can parasites communicate with one another?”

“Yes.”

“How close do they need to be?”

“They can communicate from anywhere within this nation’s borders.”

“Where are the other parasites right now?”

“Current locations unknown. My contact with them was severed upon inhabiting this body.”

Pixie continued to smoothly answer Tatsuya’s questions. Her face itself was impassive, but her thought waves sounded happy—and that probably wasn’t his imagination. He didn’t know how much in the way of emotion telepathy could express or how much of it one could disguise, but as far as he could feel, she was legitimately happy to be helping him.

To him, a monster was showing him kindness. It may have been a coldhearted way to put it, but he still couldn’t help feeling unpleasant about the whole situation. Still, since its host wasn’t a person but an object, it made it a little easier. He didn’t have to feel guilty about treating it like a possession and using it however he needed to.

It was after his questioning had just reached a breaking point that Erika came into the classroom—and saw just the two of them in it, one person and one robot.

“Tatsuya, do you have a second?”

Had she been listening in for the right moment, or was it a pure coincidence? He didn’t know. Eavesdropping he could forgive, since it was Erika and he’d been getting all his answers through active telepathy anyway. She would’ve heard only Tatsuya’s questions, no matter how hard she tried.

He didn’t have any complaints as to her suddenly coming in. It wasn’t as though he’d been in the middle of changing, and this wasn’t even his room, so he didn’t feel like demanding that she knock first. It was just that…

“I don’t mind hearing you out, but you seem like you’re out for blood. It isn’t as though I don’t feel anything, you know.”

…he wished she’d calm down a little.

“Oh, uh, sorry!”

Erika didn’t seem aware of it herself. When Tatsuya pointed it out to her, her face turned red with embarrassment.

“No, it’s okay, as long as you understand.”

She truly didn’t seem to realize it, and the coiled springlike mood clinging to her quickly dissolved into the air.

That meant that whatever she wanted to talk to him about was taking up all her mental processes. For whatever reason, he felt his sister did similar things, too, and he had to consciously suppress a dry grin from coming out.

“Pixie, please lock the door.”

“At once, sir.”

As the robot went, Erika came before Tatsuya, as if to take the robot’s place. He gestured for her to sit down, but she didn’t want to. She stayed standing, looking down at Tatsuya, who was sitting in a chair.

It wasn’t like he didn’t understand how she felt, so he didn’t force the issue. “What did you want to talk about?”

“You know what.”

“Well, I have a guess.”

“Yeah… It’s about my brother making a sorry display of himself last night.”

Erika’s answer was what he’d expected, but that hadn’t been the only thing he’d expected. “Is that all?”

“That first for now.”

I see. She has an order, Tatsuya thought.

Erika continued, “Who was he up against?”

The question was extremely forward, without any preface at all. But she hadn’t waited for him to say something before asking it—maybe it had her quite flurried.

“Commander of the Stars, of the USNA armed forces—Angie Sirius.”

Tatsuya’s answer in response was also forward and blunt.

Erika seemed at a loss, as though she hadn’t expected him to give an answer so quickly.

“What did you need to know that for?” asked Tatsuya this time, plunging into the hole her bafflement left.

“I mean…isn’t it obvious?” Erika seemed taken aback by the frank cross-questioning, but she gave an immediate, strong-willed expression as she answered him.

“I can make a good guess, but…you shouldn’t, Erika.”

“You trying to say I can’t do it?”

This wasn’t the unconscious anger from a few moments ago. Erika was quite aware of the anger she was displaying.

Tatsuya accepted it without batting an eye. “Yes. Not because of your actual abilities—but because of how it would end up.”

“…What do you mean?” Her anger swelled at the first half of his sentence, but changed to dubiousness in the second half.

“Did you see the news this morning?” he asked. “Videos or printed, either one.”

“Yeah, but which news do you mean?”

“The news of the small, drifting USNA vessel.”

“Right, that… Wait?!”

“You’re quick on the uptake.” Erika’s face had changed completely, and Tatsuya’s praise was not flattery. “Sirius probably won’t be showing up again. I don’t think anything good will come of this for either of you if you dig it back up.”

Erika didn’t give an acknowledgment or a denial to Tatsuya’s advice. “Tatsuya…” she said instead, looking at Tatsuya as though he were a strange, unknown monster. “Who…who are you…?”

No, it wasn’t “as though he were”—that was exactly how she was treating him.

“We, at least—the Chiba—we couldn’t do something like that.”

“Is that so?” Tatsuya wasn’t trying to feign innocence, but he had no other answer to give her.

“Not just us. The Isori, the Chiyoda, the Tomitsuka—I bet none of them could do it, either. I don’t know what you did or how you did it, but the only ones who could get results like that would be the Ten Master Clans, and only then the—”

“Could you give it a rest?” answered Tatsuya shortly, implying this wasn’t something he could answer.

But Erika didn’t seem to understand.

“—only a family with a lot of power. Either one with their footing in the capital or one that could operate regardless of area.”

She didn’t stop talking.

“Erika, stop.”

“Excluding the Ichijou, since they’re based in the Hokuriku district…then the Saegusa or the Juumonji. Or…the Yotsuba. Tatsuya, could…could you be—?”

“I said stop.”

“!”

Tatsuya hadn’t raised his voice with her. It wasn’t his voice’s volume that silenced her but the willpower contained within.

“Any more than this would make us both unhappy,” he told her quietly.

Erika had her fair share of experience living through savage battles.

She hadn’t gone silent because he’d overawed her.

It was precisely her densely packed experience that informed her.

She was very foolishly about to step over a boundary.