In Theory [Senku x Reader]

0.3 | What He Remembers (And What He Forgets)

Taiju wanted to reach out—to Senku, to you, to anything—but something rigid and unyielding held him still.

The dream slipped away.

.

.

.

When the world reformed, it was quieter.

Taiju blinked. The sensation was fleeting, uncertain.

It felt like he had just been somewhere else—and nowhere at the same time.

Maybe it was nothing.

Maybe he was just a little more tired than usual.

"Taiju, take a look outside!"

Something rung in his ear, clear, and light.

A familiar voice—Yuzuriha's voice. He'd recognize it anywhere.

But for some reason, it felt like he hadn't heard it in a long, long time.

His gaze followed her outstretched hand toward the window.

A classroom window.

Long white curtains shifted gently with the breeze. Late afternoon. The golden light of spring bled through the glass, casting soft shadows across the old wooden desks. The faint scent of cherry blossoms drifted in from outside, where petals swirled through the air, carried by the season's first warm wind.

"Whoa! There's so many of them, Yuzuriha!" he exclaimed, eyes wide with wonder. The petals danced, caught in invisible currents, almost like something from a nature documentary.

He was about to say exactly that—until he turned back to her.

And for a moment, just a second, the words slipped from his mind.

Yuzuriha was smiling—bright, effortless, the kind of smile that made the room feel lighter. And for a fleeting second, maybe even less, he could've sworn her hair moved like the petals outside, caught in the same unseen flow.

Meanwhile, you sat by the window, chin propped on one hand, eyes distant as you watched the trees.

Yuzuriha was beside you, humming softly as she braided a loose strand of your hair. The crisp lines of your high school uniforms contrasted against the pastel hues outside. Around her neck, her signature white headphones hung loosely, the wire swaying slightly with each movement.

Taiju watched, feeling distant, as if standing outside a moment he had once lived.

"Tch. It's just a bunch of dead petals," came a dry voice.

"Senku, no one asked."

Turning to his right, Taiju spotted his best friend sprawled lazily across a desk, textbook open, scribbling something in the margins—probably something completely unrelated to actual schoolwork. When Senku did glance at the window, he looked utterly unimpressed.

You leaned casually against the windowsill, shooting Senku an amused look, clearly entertained by the exchange.

An old routine—one the two of you had been performing for as long as Taiju could remember.

He felt something in his chest. An odd feeling that he paid no mind to.

Senku scoffed, shifting slightly. "What? It's literally biological debris. The petals fall because of programmed senescence in the abscission layer at the base of the flower—same reason leaves drop in autumn." He twirled his pen between his fingers. "It's nothing special."

Yuzuriha giggled, her face lighting up at yet another one of your and Senku's pointless debates. "Maybe, but just because something is scientific doesn't mean it can't be beautiful, right?"