Magic. A miraculous art that manifests phenomena beyond science, fueled by mana, adhering to the principle of equivalent exchange. Purely a fantasy, a dreamlike power.
Yet, in this world, magic refers to a systematized supernatural ability theorized by the late 20th century. Its rise was shaped by history. A terrorist attack targeting nuclear weapons was thwarted by a police officer wielding this power, thrusting magic into the global spotlight.
By 2035, Earth's rapid cooling strained food supplies, sparking resource conflicts and igniting the Third World War, known as the Global Outbreak War. Total nuclear annihilation was averted when mages worldwide united, developing anti-nuclear magic to neutralize warheads, saving humanity from extinction.
Nations then competed fiercely to cultivate elite mages Strategic-Class Magic Technicians, or simply "Mages" capable of wielding unparalleled power. The war, lasting two decades, halved Earth's population and reshaped nations, accelerating global reorganization. With nuclear arsenals rendered impotent, nations turned to mages as the new deterrent force.
Research revealed magic aptitude is partially hereditary, fueling unethical desires to breed superior mages. Some resorted to genetic manipulation, discarding moral boundaries. In Japan, this birthed the Ten Master Clans, including the Mitsuya Clan, and the Eighteen Auxiliary Families factions of mages exploited as tools or weapons by those seeking national dominance, clashing with traditional practitioners.
A century after magic's emergence, it remains a double-edged sword: a marvel to some, a hidden threat to those without it.
"Talk about a cliché… or maybe a trope?"
My name is Yuto Mitsuya. I'm the sixth of seven siblings two older brothers, three older sisters, one younger sister. The Mitsuya family is one of the Ten Master Clans. My father, Gen Mitsuya, fronts as an international small-arms broker.
Why the detached tone? I'm a reincarnate. No, not the "hit by a reckless truck" kind. In my past life, I was a college student who just… dropped dead. No illness, no warning just asleep, then gone. Next thing I knew, I was here, memories intact. I vaguely recall my old name, but it's irrelevant now.
At first, I thought I'd shrunk, like some detective dosed with a mystery drug. My "sister" peering at me worriedly mused, "Did the fever mess with his memory?" That stung a bit.
To her, it's a natural reaction. To me, it's pure confusion.
"Stay put. I'll get Mom," she said, leaving the room likely my bedroom, judging by the decor.
I vaguely recall meeting a goddess-like figure during the transition, but the details are fuzzy. All I know is she gifted me knowledge of this world's magic and skills. Oh, and she apologized profusely, groveling like a broken record. Probably my imagination.
A woman burst in, hugging me tightly. Her relieved tone was unmistakable. "Yuto! Thank goodness… Your psions surged wildly, and you were burning up for a full day. Are you okay?"
"I'm fine, Mom. Sorry for worrying you."
Thanks to this body's memories, I recognized her as Shiho Mitsuya, my mother. Losing memories to a fever would've been disastrous, so I'm grateful they're intact. Because, honestly, this is The Irregular at Magic High School world. That Tatsuya Shiba exists here. Talk about a stacked deck. And the Mitsuya family? We're knee-deep in complications.
Any clan with "Seven" or "Nine" in its name would've been just as troublesome. No matter where I landed, stress would've followed. I just hope my fears are unfounded, but that goddess's vague memory suggests I'm loaded with extras, making me stand out whether I like it or not.
For now, Mom mentioned an unintended magical outburst overheated my Magic Calculation Area, but the fever subsided after half a day. That area, tied to the subconscious, is tricky to tamper with. As I pondered fixing it, a magic formula assembled itself in my mind. Startling, but I kept quiet to avoid worrying Shiho. Could be a trump card mental note made.
"Rest for a few days," she instructed.
"Okay."
No health issues, but I'll obey. As she left, I lay back, itching to test that formula. No guinea pigs, though. Maybe a perception spell? Another formula completed itself. I was floored—two spells in minutes? A perk, sure, but reckless to mention. Even basic spells equate to 30,000 characters of code; these are easily seven digits. Headache-inducing stuff.
I activated the spell at minimal output. A bird's-eye view flooded my senses, like overlooking the earth. Testing my knowledge, I located the Yotsuba Clan's stronghold, piercing their recognition-inhibiting barrier effortlessly. Zooming closer risked exposure to those "Untouchables," so I stopped.
The door opened. A small girl appeared Shiho, my five-year-old sister, per this body's memories. I'm seven, by the way.
"Shina, shouldn't you be studying?"
"Y-Yuto-nii! You're awake?!"
Original timeline? No brother or sister near Shina's age. The sibling lineup's shifted, meaning this world diverges from canon. I need to move fast. Patting Shina's head, I smiled as she relaxed, beaming.
"Mom says I need rest, so I'm stuck here. Sorry for scaring you."
"No! If anything happened to you, I…"
Brother complex alert? That might thin her bond with the Yaguruma kid, our guard. Was the original Yuto a doting type, or is Shina just spoiled as the youngest? No clue.
…Maybe if I sleep, I'll wake up back home. Escapism? Laugh it off, Veggie Prince.
Days Later
"I can stand normally. Nice."
A few days post-reincarnation, I'm cleared to leave bed, doctor's orders. I'd been tinkering with a perception spell, "Kaleidoscope," while bedridden. It's a perception-type magic, but there's more to it. My abnormal hearing worse than Shina's was a hassle. Thankfully, my room's soundproofed, and noise-canceling headphones help.
The original story focused on the Yotsuba, leaving Mitsuya details scarce. If I had a classmate, I'd know more. All I know is Shina's eight years younger than her triplet siblings. One thing's clear: the Mitsuya are as indulgent as the Yotsuba.
"Yuto, you up?"
"Don't barge in without knocking, Mika-neesan."
"It's normal for siblings!"
Mika Mitsuya, third daughter, three years my senior. Carefree but caring, she skips knocking due to my hearing. Still, her habit of doting on me screams sister complex. "I'm just loving my cute siblings!" she claims.
A girl smacked Mika with a paper fan. "Ow! Who—"
"Mika, let's have a chat."
"Kana-neesan, wait! Anger's bad for you!"
"It'll only hurt at first. Yuto, borrowing her."
Kana Mitsuya, second daughter, four years older, nicknamed Mika's "Lethal Weapon." Always smiling (eyes like slits), but terrifying when mad. Second only to Mom in the household hierarchy. I just nodded.
Eldest brother Motoharu's at First High. The second brother's in ninth grade, the eldest sister in seventh. They're all protective, probably because of my fever scare.
(What now?)
I'm no Yotsuba kin, so altering this arc's tough. Best bet: avoid pissing off Onii-sama. I've got survival measures, but they're not foolproof. At seven, even as a Ten Master Clan heir, my options are limited. This world doesn't let kids act like fantasy heroes.
For now, I'll start small and adapt.
Mitsuya Household
Gen Mitsuya, clan head, sat deep in thought. Yuto's mysterious fever had alarmed him, but it subsided, and doctors found no issues. Yet, something had shifted.
"Checked by a Yoshida mage via Yaguruma connections. No parasite just him."
Yuto's behavior had changed dramatically. Once frail and reclusive, he now jogged, devoured magic texts, and hoarded CADs. Suspecting possession, Gen consulted an old-style mage, who cleared him.
"I doubted my own eyes."
Confronting Yuto, Gen demanded, "Who are you?" with a spell primed. Yuto's response shattered his expectations: "I was reborn into this body." Gen canceled the spell, stunned.
"Reincarnation? Preposterous, yet…"
Evidence supported Yuto's claim. Even Shiho and Shina's concerns about her clinginess came up. Yuto's quip "She'll never find a suitor like this" was oddly mature, though not untimely in a mage society favoring early marriage. Gen promised to consider it, chuckling at being counseled by his son.
Yuto declared, "Motoharu will inherit the clan and business. I don't want it. Family feuds only weaken us."
Gen was floored. No seven-year-old thinks like that. It confirmed Yuto's rebirth and hinted at extraordinary potential perhaps surpassing the Ten Master Clans. If so, Motoharu could be overshadowed.
Yet Yuto rejected the clan headship, citing past-life baggage and a desire to spare Motoharu displacement. Gen saw an opportunity to address the Mitsuya's subservience to the Toyama Clan.
"You're my son, Yuto. No inheritance, as you wish. Live freely—I'll bear the responsibility."
Yuto requested training at his mother's martial arts dojo, a renowned school producing soldiers and police. Motoharu resisted, but the second brother and eldest sister attended. Yuto agreed instantly, saying, "A mage's body is their capital. Honing physical skills for independence makes sense." Gen nodded, wishing Motoharu could hear it.
Yuto's talent was undeniable, a potential game-changer for the Mitsuya. As Gen gazed into his tea, he whispered, "Live fully… for the one who couldn't."
Who those words were for, only he knew.