Thursday, April 5, 2096. One day before the National Magic University’s First Affiliated High School’s new year opening ceremony, and three days before the entrance ceremony.

At the Shiba siblings’ house, Tatsuya was standing in front of a long body mirror with a distressed expression on his face.

Next to him was his younger sister Miyuki, wearing a flowering smile. In fact, it felt like the cherry blossoms would go back to being buds in embarrassment if they had to compete with such an endearing expression. That was the magic that her smiles possessed. She was so beautiful that their new roommate, Minami Sakurai—sent there by their aunt Maya Yotsuba as a housekeeper, bodyguard apprentice, and boarder—who would become their junior at First High three days from now, seemed to simply fade into the background despite standing right next to her.

Expectation glistened in Miyuki’s broad smile as she watched her brother in front of the full-length mirror. The jacket portion of Tatsuya’s new school uniform, which had arrived the day before, hung on the hanger right next to the mirror.

“Brother, please hurry and let me see what you look like in your new uniform. Or are you trying to keep your sister in suspense…?”

If he left Miyuki alone, she’d probably start overheating any second now. He decided he’d have to put aside his own gloom for the sake of his sister’s mental health. He’d already put on his uniform’s slacks and the official vest. Now he just had to throw on the blazer. Resigned, he grabbed its collar.

Minami tried to move in front of him to help him get his arms through the sleeves, but Miyuki moved at the same time, cutting her off. Without seeming particularly offended, Minami withdrew to her previous spot.

Tatsuya took the blazer from his sister’s outstretched hand and turned. After he put his arms through the sleeves, Miyuki pulled the long blazer up from his back to his shoulders, then smoothed out the wrinkles.

When Tatsuya turned back to face the mirror, Miyuki, watching him, put a hand to her cheek in rapture and let out a passionate sigh.

Its design and coloring were the same as the regular First High boys’ uniform. But there were three spots that differed slightly.

Tatsuya’s new uniform blazer: Its left breast and shoulder were decorated with an eight-toothed gear design. It was the same size as the eight-petaled flower emblem on Course 1 uniforms and had a similar design; the new emblem was embroidered onto his left breast pocket and the tops of both sleeves.

“It suits you very well, Brother…”

Tatsuya still had many reservations about the new uniform, but its design immediately cleared the resentment that was pent up in Miyuki whenever she looked at him in his uniform with the blazer’s breast pocket unadorned.

This gear emblem was a symbol of the magical engineering curriculum, newly created starting this year. The school had decided it wouldn’t be good for its reputation to continue treating Tatsuya, who had built up a repertoire of outstanding achievements over the past year that couldn’t be ignored, as a “substitute.” As a result, it had put together a new curriculum for magical engineering, abbreviated M.E.

Of course, the school couldn’t change its whole organization just for Tatsuya. Whatever the actual events leading to it were, it would be absurd for a newly created course to contain only one student.

Instead, it had made a fundamental update to the First High curriculum.

New students would be split into one hundred Course 1 students and one hundred Course 2 students; there was nothing different there.

What had changed was the process of moving from freshman to junior. New juniors now had the option to choose between the general magic curriculum and the magical engineering curriculum. Those who opted for general magic would receive lectures separately, as before, with four classes of Course 1 students and three of Course 2 students. Meanwhile, those who went for the magical engineering courses and passed the exam in March would be placed in a new class and given a curriculum that put emphasis on technological concepts relating to magic engineering.

Because it was establishing a new prototype school system, First High had also received an influx of teachers dispatched from the university. At first it would only be for one class, but in the future, if the new system saw good results, the school planned to separate the general magic and magical engineering students at enrollment and recruit new students.

And as a side effect of the M.E. courses’ establishment, however many Course 1 students moved to magical engineering, an equal number would be allowed to transfer to Course 1. The school selected the Course 2 students with the highest grades in practical fields; of Tatsuya’s friends, Mikihiko would be moving to Course 1 this year.

And yet, however they glossed over things on the surface, it was clear to those who were in the know that the magical engineering curriculum had been established for Tatsuya.

So you couldn’t exactly blame Miyuki for celebrating her brother’s long-awaited triumph.

Several forced poses later, Miyuki seemed satisfied and finally permitted Tatsuya to change. He felt a little like she was using him as a dress-up doll, but he convinced himself it made sense because she was still a girl. (The fashion show for Minami, the new student, had been three days before.)

“Brother, Minami, why don’t we have some tea?” said Miyuki to her housemates, her good mood lingering, before disappearing into the kitchen almost at a skip. Minami watched her go and lowered her eyes sadly, which was already a sight Tatsuya was accustomed to. She was young—practically a child, in fact—but a spirit of professionalism had been instilled in her. As far as he could tell, she approached her maid work with pride (though that, too, was a fairly impolite impression). For her, someone else preparing tea probably challenged her reason for existing. Still, it didn’t seem like Miyuki had any wish to yield when it came to the importance of taking care of him. The first five days after Minami’s arrival had seen the girls making fairly bitter deals with smiles on their faces. Had Tatsuya’s heart been of weaker constitution, he might have complained that his stomach hurt and left. Thankfully (?), though, he was built like steel, mentally and physically.

At the end of their quiet warfare with their identities at stake, Miyuki and Minami had come to a vague compromise.

First, Miyuki would leave cleaning and laundry to Minami.

Second, Miyuki would leave tea and cleaning up after meals to Minami.

Third, Miyuki would see to meal preparation when Tatsuya was present. When he wasn’t, Minami would make the food.

Fourth, Miyuki would see to tea preparation when Tatsuya was present. When he wasn’t, Minami would prepare it.

Fifth, Miyuki would help with Tatsuya’s dress. Minami would help with Miyuki’s.

The reason this arrangement was vague was that either of them, if she saw an opportunity, would attempt to outwit the other. As far as Tatsuya could tell, though, their relationship for the moment was peaceful and friendly.

Tatsuya and Minami’s relationship was, on the surface, also friendly. Of course, he figured—as though it didn’t concern him—that if a boy going on seventeen and a girl who was currently fifteen were to grow completely comfortable around each other in just two weeks, that might actually be a bigger problem.

Still, the fact was that Tatsuya felt like keeping something between them—specifically distance. Her slightly down-slanted eyes, her wavy dark-brown hair, her slender yet thick eyebrows, and the way dimples appeared in either cheek when she smiled all reminded him too much of Honami.

Honami Sakurai: the woman who had been their late mother’s Guardian. Someone who had passed away four years ago protecting Tatsuya in Okinawa.

Minami and Honami had had the same “mother.” They had been “created” from the same batch of unfertilized eggs and undergone the same genetic modification, and then those eggs had been fertilized by sperm gathered from the same “father.” A human genetically engineered to have a strengthened magic faculties—an engineered magician. They were “sisters,” not twins but extremely close to being so. It only made sense that Minami, genetically a niece, would have such similar features to Honami.

Tatsuya knew all the logic, of course. But understanding it didn’t solve the problem or grant him comfort. The reason the “thing between them” (or something like it) had emerged in Tatsuya wasn’t her appearance itself, but the memories of the dead her appearance triggered.

To the Shiba siblings, Honami Sakurai had been like family. She’d been like an older sister, easy to get along with. When Miyuki thought about her, she grew full of both mourning and fondness. But Tatsuya felt more bitter regret than anything else. Even the memories of her taking the siblings to her heart were like bitter gourds that only amplified his regret. It wasn’t that the gourds were inedible—it was that his face would scowl without his meaning it to.

He hadn’t been strong enough.

That was, in a few words, a summary of the regrets Tatsuya had when it came to Honami.

She’d died of emaciation, but if Tatsuya hadn’t tried to intercept the GAA fleet invading Okinawa, she wouldn’t have had to die there, at least. The truth was that Honami had whittled down her life until it was a cinder via continuous application of large-scale magic to protect Tatsuya.

Tatsuya, however, didn’t regret the decision itself. He didn’t consider the choice to intercept to be wrong. He hadn’t thought deeply about his actions at the time—they’d been the result of swelling emotions. But if he hadn’t wiped out the GAA ships then and there, it was highly likely the situation would have gotten even worse. He wasn’t the only one to believe that, either. The tactical simulations done at the Academy of Defense’s lab had produced the same results.

His regret was having needed Honami’s strength at all.

These days, Tatsuya didn’t need much time to prepare Material Burst. Now that he’d learned to fire Dismantle as a stationary area-of-effect spell, he wouldn’t need Honami to help him shoot down the enemy warships’ artillery shells.

At the time, he hadn’t had enough strength.

And now, when he saw Minami, it reminded him of how powerless he’d been back then.

“Brother?”

“Right, I’m coming.”

Tatsuya had been trapped by pensiveness for no more than three seconds. Miyuki hadn’t given him the prompting because time had passed, but because she had noticed the slight change in his mood.

In response, Tatsuya began to move.

Minami, who had been waiting for him, followed behind.

The siblings had essentially been living on their own, and just having an extra housemate meant they had to buy more of certain things and replacements for others. Their dining table was one of them. The new table, one size larger than its predecessor, had a surface made of heat-resistant, high-strength glass, its emphasis heavily on its design element. Still, it was quite a bit sturdier than plywood, so unless someone used a big two-handed hammer, it wasn’t going to break. Considering its resistance to moisture, stains, and grease, it was actually highly practical as well—which, of course, meant it was on the expensive side. When Tatsuya sat down at it, Miyuki sat down across from him, and Minami next to her.

Miyuki, for some reason, was still wearing her apron. Minami wore an apron by default, and having two girls in aprons sitting across from him was an odd situation, now that Tatsuya thought about it.

Of course, they may have both been wearing aprons, but their fashion sense was significantly different.

Minami wore a simple, long-sleeved, long-length, high-necked dress. Her apron, too, was made of thick fabric that covered almost the entire front of her body—a design that stressed practicality above all else. It wasn’t the style of “real” maids from nineteenth-century Europe, but it clearly had that in mind.

In contrast, Miyuki was wearing a bold off-the-shoulder minidress, despite it still being early spring. Her apron was the type that hung by slender braids as well—how many different aprons did she even have?—and it even revealed her clavicle. Her skirt ended over ten centimeters above the knee, and she was barefoot below it as though it were natural. He could see a fair bit of her thighs through the highly transparent glass table, brought together as they were in a ladylike manner.

Could his sister have been trying to seduce him—or was she just teasing him?

That has to be it. If I let it get to me, I lose, he decided, glad that he wouldn’t need to worry about it even if it was true. He decided he should thank his mother and aunt for that—though Miyuki was likely of the opposite opinion.

Neither of the siblings breathed a word about any of that, though, and they each aimed for their own coffee cup and cookies.

“The entrance ceremony is in just three days. I’m sure you’re excited, aren’t you, Minami?”

Nothing like it had happened when they’d lived on their own, but Miyuki had recently gained a tendency to swing the conversation to Minami whenever Tatsuya fell short of her expectations.

“Yes, Big Sister Miyuki. I am excited.”

Meanwhile Minami, whether she hadn’t caught on to Miyuki’s intent or did but couldn’t do anything about it in her position, gave a much more sincere reply to her offhanded question.

“Miyuki and I have to go to school a little early that day. Is that okay with you, Minami?”

“That’s fine, Big Brother Tatsuya. I will humbly accompany you both.”

Incidentally, her “big sister/big brother” references were something Tatsuya had suggested and Miyuki had subsequently ordered.

Because of how cabinets—the modern-day public transportation system—worked, they’d never be riding with complete strangers. Nor could they meet up with others part of the way through the trip. If people were riding the same cabinet, they had to live in the same house, live extremely near each other, or at least meet up at the station first.

On the other hand, because of her additional role as bodyguard, Minami didn’t have the option of going to school via a different cabinet from Miyuki. Still, it would be unnatural for a complete stranger to commute in the same cabinet every day—it would invite suspicion they didn’t need.

The excuse they’d be using was that Minami was the siblings’ cousin on their mother’s side. The Yotsuba family had instructed them to tell people something to that effect as well, and besides, the siblings’ family register was utterly red with lies already. Adding in a cousin not related by blood was trivial at this point.

The problem had been in how Minami had initially referred to them as “Lady Miyuki” and “Lord Tatsuya.”

These days, save for a few exceptions, no high school girls used the term Lady or Lord for students one year their senior. Those exceptions were girls of high birth, servants in the employ of high families, and girls somehow otherwise belonging to high families. Magicians only used it for people from the Ten Master Clans or families of equal import. Big Brother and Big Sister were exaggerated, too, but they were more common forms of address than Lord or Lady.

Tatsuya and Miyuki really just wanted her to call them by their first names, but Minami rejected that out of hand. She’d expressed reluctance at the family relation tags, too, but she knew concealing their identities was of great import, and so they’d compromised on Big Sister Miyuki and Big Brother Tatsuya.

The siblings, who had been living on their own, were for the moment getting along well with their unexpected new housemate.

Their teatime topic, naturally, shifted to the entrance ceremony three days hence.

“This year’s representative is a boy… First time in four years, is it?”

“Five years, Brother. The president before Saegusa was a girl as well.”

The siblings’ conversation had turned to this year’s new student representative—in other words, the top-seated incoming freshman. It had been a long time since First High had seen a boy as the representative.

“Since Saegusa’s little sisters are enrolling this year, I thought it would be a girl again.”

“Yes…and if Minami had really tried on the exam, she probably would have been the representative.”

“No, that would be out of the question…”

Minami, expression stiff, shook her head a little at Miyuki’s slight tease. The fact was that she had been concealing the true extent of her magic power on the main family’s orders so that she wouldn’t stand out too much. Tatsuya agreed that if she’d taken the test for real, she probably could have taken the top seat, but it seemed Minami wasn’t of a mind to let a conversation like this pass without saying something.

Before an awkward air could begin to drift, Tatsuya decided to get back to the topic. “His name is Takuma Shippou, right? The Shippou?”

Miyuki hadn’t exactly wanted to trouble Minami, either. She followed her brother’s intentions right away. “Yes—eldest son of the Shippou, of the Eighteen.”

The family tree of influential magicians in Tatsuya’s mind and the information Miyuki recalled from the student profiles in her memory came to matching conclusions:

“So we have the Saegusa and Shippou as classmates. Either it’s an incredible coincidence, or some very deep-rooted fate… I hope it doesn’t cause any trouble,” muttered Tatsuya, frowning just a little.

“Wouldn’t it be good camouflage for us if they did stir up a little bit of trouble?”

“Well, yes, but…”

Miyuki meant that if the eldest son of the Shippou and the Saegusa twins were to get into an altercation, the school’s attention would be on them, meaning there would be nobody—or at least fewer people—left to poke into the relationship between the siblings and Minami.

Her comment was logical, but he started to get a headache when he considered who would have to settle the commotion.

“Oh, and about the party tonight…”

As Minami was about to get up and clear the table now that their cups and saucers were empty, Tatsuya gestured for her to stop and suddenly changed the topic.

“I still think Minami should attend as well.”

Tatsuya and Miyuki had been invited to a party at the Kitayama residence (meaning Shizuku’s house) that night. The plan wasn’t for Minami to mind the house in their absence, but for her to come with them to the mansion and wait for them in the servants’ waiting room, but Tatsuya thought that they should change it.

“If you order me to, I will obey.”

Minami’s response was the reasonable one for a servant. But her expression was especially impassive now, implying that she didn’t really want to do it. Her features weren’t very expressive, but she certainly wasn’t emotionless. Compared to girls like Mayumi or Erika, who would deliberately construct overblown expressions, Minami had emotions that were easy to read—though of course, this was only due to Tatsuya’s own insightfulness.

Tatsuya wasn’t into forcing people to do things. He took no pleasure in ordering people to do things they disliked. Her answer that she’d obey if ordered was something he was reluctant to exploit, and it actually made him want to say, You know what, never mind, but he hadn’t made his previous comment on a whim.

“I see. I know it might be difficult, but please do come with us.”

He considered it necessary that she reinforce the lie that she was their maternal cousin, so a somewhat unhappy answer in response wasn’t enough for him to withdraw the idea.

“Let’s pick you out a dress right away. I’ll help you, since we don’t have very much time.” Miyuki clapped her hands, her mood changing to a cheerful one, perhaps in consideration of her brother’s unshown feelings on the matter.

It was certainly not—he was sure—because she wanted to see Minami getting incredibly flustered.