As the residence of a British diplomat stationed in Japan, the Sawamura family had long lived in a luxurious, manor-style villa located on the outskirts of the city.
In Sawamura Eriri's memories, aside from her parents—who only occasionally returned home—the only ones who kept her company in this vast, castle-like residence were the servants and the butler.
—Of course, that was only true up until now.
In the grand hall on the first floor of the villa, the blonde girl sat properly at the long dining table enjoying breakfast. She rubbed the hair she had just finished blow-drying, taking small bites of her food while using the corner of her eye to size up the golden-haired, curly-headed boy seated across from her.
She knew this person. No—she knew him so well that it felt like looking at another version of herself.
Sitting straight across from her, eating breakfast at an unhurried pace, with a bandage stuck to his forehead, was her twin brother—Sawamura Spencer Tōru.
Gradually, countless memories involving him—memories deeply intertwined with her own—began surfacing in Eriri's mind.
More than a decade ago, when Mrs. Sawamura was rushed to the hospital to give birth, the couple were delighted to discover they were about to welcome a set of boy-girl twins. After the children were born safely, the overjoyed first-time parents poured all their energy into raising them.
Born into the family of a British diplomat stationed in Japan, the children should have enjoyed material conditions far beyond those of ordinary people. However, because their father was not the type who favored special treatment, both twins still attended public elementary and middle schools.
Up to this point, everything still matched Eriri's original memories.
But there were subtle differences—small deviations from what she had personally experienced.
For example, the one who drew people's gazes wherever they went, the one who was watched by classmates with a mix of admiration and distant reverence, was no longer herself.
Even though she still held the title of "Toyogasaki Academy's Public Beauty," the one standing on equal footing with her was no longer merely another girl praised as a beautiful novelist.
If one were to ask who the most prominent figure at school was, the first name that would come up was undoubtedly her brother, known as the "Prince of Toyogasaki Academy."
Like her, he entered the school as a mixed-heritage student. He studied in the same class as her, shared the same privileged family background and striking looks—yet he had become the true center of attention.
As for why, it was probably because Tōru possessed everything Eriri herself was praised for, and then some. He had excellent grades and a diligent, driven attitude. In the eyes of teachers, classmates, parents, and relatives alike, he was a once-in-a-generation prodigy.
Compared to that, Eriri—who, despite being mixed-heritage, frequently failed English exams and consistently ranked near the bottom academically—couldn't help but feel inferior.
Other people's kids weren't scary. What was scary was that this one was her peer.
And because she had grown up under the shadow of her brother's brilliance, Eriri had always harbored a fair amount of dissatisfaction toward him. As a result, their sibling relationship was never as close or harmonious as those of other families.
"..."
Despite it being a breakfast meant only for the two of them, an awkward silence filled the air.
Her big brother wasn't just handsome and academically outstanding—he was also a great cook. As Eriri enjoyed the bacon-and-egg wrap sandwich he had just made, she stole subtle glances at the golden-haired boy chewing slowly and methodically.
Although a brother had suddenly appeared out of nowhere, the memories flooding into her mind made it feel as though the decade-plus she had spent living alongside him wasn't fake compared to her previous life. That natural sense of familiarity and closeness made her curious about what her brother was thinking right now.
Of course, if she truly could read minds, she would have been utterly shocked by the real thoughts hidden beneath her brother's calm exterior.
"The 'Prince of Toyogasaki Academy'… isn't that title way too chūnibyō? And wait, does that mean this simulation is sending me down some kind of forbidden sibling route? They dumped all this information on me right from the start, even messing with my family background and my name—this seriously kills the immersion."
Narumi—he still wasn't willing to fully call himself "Sawamura Tōru"—pretended not to notice Eriri's obvious glances while internally complaining about the system's unreasonable setup.
Everything Eriri remembered had, naturally, also poured into his mind as information from the past decade.
A pampered upbringing, a status adored by all, a life that had been favorably viewed by parents and teachers alike up to this point—this was the life he had been given in this simulation.
And within that life, the most abrupt and noteworthy presence was, without a doubt, his younger sister Eriri.
[Please consider this a matter of narrative necessity and forgive us—however, in order to set your starting point under conditions like the Sawamura household, I trust you can understand this necessary sacrifice.]
"Mm… how should I put it? It feels kind of… delicate."
After all, the "real self" wasn't something he could trade away so lightly. If one could discard anything at will, they'd eventually be left with nothing at all.
[But please rest assured. The random attributes you obtained this time do not include personality traits, so you needn't worry about synchronizing your conduct or values. You may act entirely according to your own judgment.]
The system seemed to sense his concerns and hurried to patch things up with those words.
[This time, please live your life to the fullest as "someone else's kid," and enjoy a different kind of existence.]
"Well, that's true and all…"
Narumi took a bite of the bacon-and-egg wrap sandwich he had made himself. In real life, he was just an ordinary high school boy who could barely cook simple meals to stave off hunger—instant noodles were his specialty.
But going from a laid-back, unreliable ordinary student to a spotlight-stealing star overnight still required some adjustment time.
"By the way, my social stats right now are probably higher than Yukinoshita's or even Hayama's, huh? A mixed-heritage handsome guy with top grades… yeah, that's already way beyond the level of a sunny normie. No matter what, I'd be the most popular guy in school."
If he could run into Yukinoshita or Hayama from the simulation in this state, that might actually be pretty interesting. No—if he could meet Hikigaya instead, that would be even more entertaining…
As Narumi slowly worked through both his breakfast and the memories he'd accumulated so far, his wandering gaze suddenly met Eriri's eyes—she had been secretly staring at him the whole time.
Like she'd stepped on a landmine, she immediately looked away, feigning indifference as she hastily finished the rest of her sandwich wrap.
"I'm done."
With that curt declaration, she stood up and returned to her room, leaving the vast hall with only the boy seated at the dining table.
He shook his head slightly and continued eating his breakfast, not particularly surprised by how things had turned out.
"As expected… my little sister can't possibly be this cute."