Unity gave wings to Karen.

But I didn’t have those wings.

I, Serika Kurose, and my twin sister Karen, were both born with exceptional intelligence.

It wasn’t inherited through blood—it was more like a sudden mutation. Our parents were the type who dropped out of school early, academically speaking.

Generally referred to as “gifted.” Meaning, talent bestowed by God.

Even as preschoolers, both Karen and I could already solve elementary school-level tests, and our IQ test results were remarkably high, far surpassing others.

I haven't looked at the answer key, so I don't know the details, nor do I care—but I do remember having the thought, "I don't understand what's difficult about this, nor do I see what's impressive about solving it."

People often assume that since my face is the same as Karen's, our abilities must be identical, but of course, Karen and I are different people. It's impossible that we have the same abilities.

—I still clearly remember the moment I first truly realized this, the moment I began to feel inferior to my younger sister.

It was when Karen found a software called Unity and we both created separate games.

I had been experimenting with programming languages since I was much younger, and at first, I was the more skilled of the two. But when it came to game development, Karen's talent truly awakened.

Until then, no matter what we did, I was slightly better. To me, Karen was a cute little sister with a few quirks.

At least, that's how it was back then.

But it was wrong. The real genius was Karen.

The reviews of the finished game were worlds apart between mine and hers.

Even though there were still rough parts, her creation was full of originality. If we had released it, it would have instantly become a sensation—despite being an indie game, it earned an amount far beyond what a child could ever afford.

This was—back then.

◇◆◆◆◇

"Hey, Serikan! You know this? There's a programming software for making games, and it's free!"

"Really? Let me see... Wow... It's the same environment as pros use. Sounds fun!"

What my younger sister Karen found was Unity, a comprehensive game engine that anyone can install and use personally. It has pricing based on revenue, and it says here that it's completely free up to $100,000 in annual sales—effectively the same as using it for free indefinitely.

"Hmm. It uses C# as its programming language. If that's the case, we could probably make a game ourselves, right?"

"We could, we could. I've already played around with it a bit, and the only real issue is creating images, that's all."

Since we'd already had some experience with programming and had even made small apps just for fun, it seemed likely that, as Karen said, the main challenge would be image creation. We could use free music, and we could figure out what kind of game to make later.

Actually, maybe even images wouldn't be a problem if we just combined free assets.

I was excited about creating a game of my own. Karin was unusually enthusiastic. I like games too, but Karin is the type who gets deeply absorbed, so she might have had an idea for a game she wanted to make.

"Making a game? You did want to try that, right? With summer break coming up, it's perfect."

"Isn't it? Isn't it? Want to make one together?"

"Hmm... since it's a good chance, maybe I'll try making one alone. I want to learn the basics by doing it myself."

"Ohhh~"

At that time, we both already had high-spec PCs, and creating a game—especially something a beginner could make—was no problem at all.

I researched indie games and older titles to understand what kinds of games sell well, and based on the principles of what makes games enjoyable to humans, I created a side-scrolling action game where players receive rewards every time a character takes action.

A cute, partially naked girl defeats monsters while gradually upgrading her gear, learning magic, and growing stronger.

Since everything except the character's pixel art was made using freely available assets, it took less time than expected, and I completed the game—including adjustments and debugging—within one month.

It received positive feedback from my brother and Nanami-senpai, so I confidently released this game into the indie game market.

I earned enough money for a month's worth of work, which I suppose was due to the game being an endless side-scrolling action title with selectable language options. It sold slightly better overseas than in Japan.

It briefly climbed to the very bottom of the rankings. Even so, I was incredibly proud as a grade schooler—my creation had been recognized by the world. I truly felt that way.

Meanwhile, Karen was completely absorbed in game development but couldn't seem to finish it, ultimately taking nearly half a year.

I had no idea what kind of game she was making—she kept evading my questions with "It's a secret, mion!"

As for me, I had already begun developing a new game based on lessons learned from the previous one, becoming utterly engrossed in it and barely paying attention to what Karen was doing.

"It's done! ~~~~"

Kareen declared her Master Up just before winter break.

Honestly, I hadn't expected much from her game.

It was something made by my somewhat clumsy younger sister.

Cute but unfriendly, flavorful yet baffling—something that would surely appeal only to a particular kind of person, I half-expected.

And in a way, that instinct was correct.

The problem is, I couldn't have predicted that her game wasn't the kind of thing you'd discuss on that level.

"So, what kind of game did you make? Action? Shooting? Maybe a puzzle game?"

"Genre? Hmm... I guess it's like a TUEEEE simulation or something?"

"A TUEE simulation? What's that?"

"Well, try it out. You never know."

I sat in front of Karen's computer and clicked on the newly created game icon.

The words "wonderful after life" appeared on a simple black screen.

Clicking on NEW LIFE instead of NEW GAME led to yet another minimal screen.

<What is your real name?>

"Ah, I see—here I have to write my real name."

"Then, Croce Serika..."

As I typed that, the screen went dark again, and words emerged in a Ming-style font.

<Serika... Serika... awaken. Pure soul... Before your journey to the new world, I have a few questions for you... Answer truthfully...>

After that, quite a number of questions were presented.

"Gender," "Age," "Occupation," "Relationship status," "Marital history," "Preferred type," "Which role would I play in a hero's party?" "Which would I prioritize—money or passion?" "Do I like my job?" "Academic performance in school?" "Favorite sport?" "What kind of death would I prefer?" "What kind of death do I hate the most?" "Am I the type who works steadily or cramming at the last minute?" "Favorite color?" "Which game do I like the most among these?" "Which is stronger—incantation magic or non-incantation magic?" "Favorite monster?" "Favorite spell?" and so on, and so on, and so on.

"Wow, there are so many questions!"

"Well, that's the whole point of this game, so there you go."

Seriously, isn't there at least a hundred questions? It's multiple choice, so it's fine, but still, that's an insane amount.

Once the questions were over, the game finally began.

In short, the game was an RPG.

But the game screen is surprisingly simple, mostly consisting of text information. It's like a mix of a text novel and an RPG, allowing you to play the game as if you're reading a novel.

The protagonist, "me," is the reincarnated form of Crosseselica, starting as a baby. The setting is that of a daughter in the village chief's family in a poor village, with two older brothers and one younger sister.

I gradually learn magic on my own, grow stronger, and defeat the goblins that appear in the village using that magic—

"…Doesn't this plot kind of remind you of a fantasy manga I read before? This one."

"Yeah, yeah. It's very much the kind of plot that would happen in a Serikan story."

"What do you mean?"

"For now, just save and try starting over from the beginning."

"Huh? Okay, fine… Wait, are we doing that same question barrage again?"

"That's right, yep."

Still, those 100 questions are clearly the core of the game, so there's nothing I can do about it.

"Hey, this time don't think about yourself—just answer freely."

I did as told, randomly answering questions with made-up details like gender and age.

Then—

"Wait, this is completely off track!"

"Hehe, looks like I drew a villainess reincarnation this time. Maybe the usual plot progression is just a testament to Serikan's charm."

I was the daughter of a noble in a certain kingdom, and the prince had just broken off our engagement.

Two options appeared: "Why?!" and "I understand." I chose "I understand," and suddenly the protagonist shouted, "Phew! Now I'm free!" before fleeing the party hall and heading back home in a carriage.

After that, I did whatever I wanted now that I was free—prospecting new territories, meeting a handsome adventurer and joining forces with him to form a party and dive into dungeons.

My character, the protagonist, is absurdly strong despite being level one, making the game ridiculously easy, but it's oddly fun and silly how my party members keep being amazed at my power.

Still, this isn't how the story was supposed to go on my first playthrough.

"…Hey, Karen. Just what exactly is this game?"

That's why I'm the TUEEE Simulator. It's a game where you can dive into countless worlds of isekai transfers or reincarnations. Depending on your choices, there are about 5,000 different ways to start. Plus, there are 20 different worlds, and if you account for tiny variations in choices, the number of possible patterns is practically infinite. Well, sure, there are quite a few starting scenarios that immediately put you in a tight spot, but still...

"W-wait, what?!"

I played it a few more times after that, and each time the story began in a completely different way—like "a boy who pulled the legendary sword," "a girl dragged along in the mass transfer of her entire class," or "a king of a small country surrounded by enemy nations."

I tried playing through one story I really liked all the way to the end, but the game itself seemed to be cleared by meeting the set conditions for each scenario—whether it was defeating the demon king, the enemy country's king, sometimes even the boss goblin, or completing a marriage, for example.

The playtime was around six hours.

Still, there was a fresh kind of fun in not knowing exactly what kind of game it would turn out to be.

"This is… surprisingly well-made. How much can you actually fit with just text information?"

"Since we're using language-processing AI, we focused more on integrating it into the game mechanics. We fine-tuned it specifically for this game, which took some time, but I think it turned out pretty well."

"So, you're saying the story is automatically generated?"

"That's right. You accumulate flags through character actions, and then events trigger or character dialogue changes based on those flags. It won't work on its own, so keep that in mind."

"Is that so..."

While I was making my typical, conventional game, Karen was genuinely creating something entirely new.

But at this point, I didn't yet feel inferior.

It's an interesting attempt, but the visuals are simple, and it doesn't always lead to a cathartic resolution—sometimes it even results in a truly frustrating, bad ending.

I figured it would definitely get harsh reviews and sell poorly, ending up forgotten.

Still, it's undeniably original, and only someone like Karen—obsessed with otaku culture and exceptionally strong on PC—could have made something like this.

But this is clearly a disposable piece of work. One that would grow tiresome after just two playthroughs.

I didn't think it would sell at all.

I figured it’d probably sell about as well as me—or maybe even less.

But the outcome was completely different from what I’d imagined.

"Look, look—there’s actually a huge reaction! People are even sharing screenshots on Twitter about what kind of reincarnation they ended up in!"

"Y-yeah…"

"It’s even ranked first on the indie chart! This is my time to shine! Well, at least in Japan."

"That’s amazing, Karen… really."

I couldn’t even muster a proper compliment.

I was stunned by the unfamiliar emotion swirling in my chest.

Is this… inferiority? Is this… jealousy?

In the end, Karen became a renowned child prodigy game developer.

Both Karin and I were already fairly well-known as prodigy elementary school students, but when it came to displaying our genius in this particular way, the reactions from those around us were entirely different.

There's a vast difference between being "incredibly good at studying for a child" and being a "grade school creator"—they may seem similar, but they're on completely different levels.

"……I was just an ordinary person all along."

A child prodigy at ten, a gifted youth at fifteen, just an ordinary person past twenty.

I was precisely the kind of prodigy who fits that description, while the true gifted one—the one truly blessed by God with talent—was Karin.

From that day forward, I resolved to become the "strongest ordinary person."

I focused on things Karin couldn't do, especially improving my interpersonal communication skills.

Looking back now, I suppose I was oddly clever for a child, acting foolishly, but at the time, losing to Karen was a shock so overwhelming it felt like the world had turned upside down. It was the moment I realized I wasn't the all-powerful being I'd vaguely believed myself to be.

And above all, it was the moment I truly understood, in the deepest sense, that even as twins, we were completely different people.

◇◆◆◆◇

I accidentally overheard my younger sister, Celia, muttering, "I was just an ordinary person, weren't I?"

(Is she serious...? Genius really is a little crazy, huh...)

Unlike Karen's game, which only gained attention in Japan, Celia's game became a worldwide bestseller.

The price is just a few dollars, yet its total sales exceed Karen's, and most importantly, unlike Karen's divisive game, 95% of reviews for Serika's game are marked "recommended"—a near-universal acclaim.

For a game made by an elementary school student, this result is nothing short of extraordinary.

True, Karen may be the more talented artist, but commercially, Serika is clearly the superior.

Moreover, while Karen releases one game, Serika has released three distinctly different titles—starting with a side-scrolling action game, followed by a shooter and a puzzle game, in rapid succession.

If Serika is just an ordinary person, then what exactly are Nanami and I?

I guess I really am a little awkward around my sisters.