Unknown Variables

Chapter 9: Proofs and Parallels

The next day at school, everything felt... uneven.

Hana smiled the same. Spoke the same. Walked beside me as if nothing had changed.

But I could feel it—the tiny shift. Like a pencil rolling across a flat desk, just barely moving, but moving all the same.

We walked to class together, yet it felt like we were on different sides of a thin glass wall.

During math club, I got called to help prep for the prefectural mock tests. The usual stuff. Solve. Explain. Smile. But as I stood by the board, chalk in hand, my eyes drifted to the door.

Sora stood there.

Not part of the club. Not saying anything.
Just... watching.

Our eyes met. She offered a small wave.

I wanted to walk out right then and talk to her.
But I didn't.

Afterward, I found her waiting outside under the overhang.

"You were good in there," she said. "You always explain like you're talking to one person."

I laughed. "That's because I imagine it's you. Makes it easier."

She blinked, surprised. Then smiled—a real one.

But then, quiet: "I heard about Hana."

I didn't pretend I didn't know what she meant.

"She told me," I said. "Last night."

"And?"

I hesitated. "I was surprised. But also... not. I just didn't want it to be true."

Her eyes softened. "That's cruel."

"I know," I said. "I didn't mean to be. I'm just trying to figure out what's real."

"You're the math guy. Isn't proof what you live for?"

I looked down. "Some things can't be proven. Only... felt."

She nodded, and then turned away slightly. "I was going to write you another letter," she said, almost whispering. "But I didn't want to compete anymore."

My heart caught.

"You were the only one who wasn't pretending," I said. "That's why I kept looking for you. Even before I knew what it meant."

Sora looked at me then, her expression unreadable.

Then she said it—soft, like folding paper:

"You were never the unknown variable to me."

She walked away before I could respond.

That night, I found no letter in my locker.

No Sora.

No Hana.

Just silence.

And for the first time, I realized something:

The hardest equations aren't the ones with no answers.
They're the ones with too many.