In Theory [Senku x Reader]

"In the depth of winter, I finally learned that within me there lay an invincible summer." – Albert Camus

The winters you remember were always bitter.

It made the city feel different– quieter, slower like time itself was caught under the weight of the sky.

The air seemed to drain the world of color, reducing it to a grayscale landscape where white reigned supreme, interrupted only by the faintest variations of off-white. Snow blanketed everything—rooftops, sidewalks, even the neglected traffic cones and recycling bins lining the streets—softening the world's usual sharp edges, muting the sounds that normally echoed between storefronts.

Above, snowflakes drifted lazily, weaving intricate, brushstroke-like patterns in the air before surrendering to gravity's pull. They landed briefly on your outstretched palms, fragile and fleeting, only to dissolve into droplets at the barest touch of your warmth. You frowned, watching the way they stubbornly endured on the frozen ground yet refused to remain in your grasp.

A voice beside you, far too knowing, broke the quiet.

"It's called—"

"I didn't ask."

Senku huffed, exhaling sharply against the scarf his father had forced him to wear. His hands burrowed deeper into his coat pockets as he turned his gaze away as if the winter chill personally offended him.

"Wow," he muttered, voice dry. "Someone's feeling chatty today."

"Yeah, well, it's a special occasion," you shot back. "I only get this pleasant when I'm freezing to death."

Senku snorted. "Right, because sarcasm's gonna raise your core temperature. Real effective strategy there."

"Please." You tucked your chin deeper into your scarf. "If I'm stuck out here with you, my survival instincts are clearly shot anyway."

"Tch. Just admit you're curious."

"About what?"

Senku gestured vaguely at the air. "The snow."

"Yeah, no thanks. I'd rather not hear your 40-page thesis on the molecular structure of ice crystals."

"Bold of you to assume I'd waste my breath dumbing it down for you."

You scoffed, more amused than annoyed. "Gee, thanks."

From the corner of your eye, you caught him studying you—analyzing, calculating as if attempting to decode some complex formula. The problem, of course, was that human emotion had never quite fit into his equations.

After a beat, he shrugged, either giving up or deeming the matter beneath his attention.

The two of you walked in near silence, the empty streets stretching ahead, save for the occasional car rolling by and the soft crunch of snow under your feet. The air clung to your skin, sharp and biting—a cold that seemed to seep into your bones.

Then, finally—

"You're mad," he noted, voice as flat as the observation itself.

"No, I'm not."

"You are."

"I'm not."

"Yeah?" He kicked a clump of snow in your direction, not enough to hit you—just enough to be irritating. "You're practically steaming."

You shot him a glare. "Oh, look at you—applying basic thermodynamics to human emotion. Must be exhausting, being that smart all the time."

"Wouldn't know," Senku shot back, smirking. "I'm just built different."