The Science of Connection (Senku Ishigami x Reader)

Chapter 16- Full Throttle Science

"We'll keep it simple—a four-wheeled frame reinforced with bamboo and wood."

You leaned over, pointing at his diagram. "If we're powering it with a wobbler engine, we'll need a lightweight design so the steam pressure can actually move it."

"Exactly," Senku nodded. "The wobbler's a basic oscillating steam engine—no need for valves, and it runs on pressurized water. Easy to build and perfect for a rough, bumpy road."

~~~ The Day Before the Rescue~~~

The wind was softer now. Around you, the field camp buzzed with quiet tension—everyone preparing for the coming rescue. Chrome's life depended on what happened tomorrow.

But in this sliver of calm, Senku sat beside you, half-leaning against the Steam Gorilla. Firelight flickered across his face, and in his hand, he toyed with something you recognized immediately: the rocket-shaped pendant you had made him for his birthday.

Lapis lazuli caught the glow of the flames, deep blue like a twilight sky.

"You know," Senku began, voice quieter than usual, "I ran a few hypothetical models in my head about tomorrow. About our odds, how the attack might go. Factoring in Tsukasa's manpower, terrain, our tech... Chrome's probably in some holding cell on the side of the mountain. Maybe not even shackled. I accounted for everything."

You raised an eyebrow, watching him. "Of course you did."

He smirked, eyes still on the pendant. "But no matter how many variables I include, there's one I can't account for."

You tilted your head. "Which is?"

"You."

Your breath hitched a little.

Senku glanced at you then, and for once, he wasn't grinning or joking. He looked serious. Focused—like you were his newest invention, the next big discovery he couldn't quite crack.

"You mess with my calculations," he continued, like he was explaining a tricky formula. "My heart rate elevates around you. I get distracted. My thoughts loop like a faulty motor. From a scientific standpoint, it's... inefficient."

You blinked, stunned for a second.

"So you're saying I ruin your science?" you asked, only half teasing.

He chuckled under his breath. "No. I'm saying... you're the anomaly that makes science exciting again."

You stared at him, heart fluttering like a misfiring capacitor.

"I can break down chemical reactions in seconds," he said, fingers now curled around the pendant. "But I still haven't found a formula for why you're the first thing I think about when I wake up and the last variable in my mind before I fall asleep."

A silence fell between you again, but it wasn't empty. It was charged.

Senku didn't reach out, didn't push for an answer. He simply looked at you, the faintest of smiles pulling at his lips.

"I don't know what this is," he admitted. "But whatever it is... I'd like to keep running tests. Together."

You stared at him.

Senku's hand lingered in yours, roughened from months of work, yet warm—familiar. Safe.

You glanced down at your fingers entwined, then back up at him, your voice barely above a whisper.
"We started this as a behavioral study. Remember?"

A slow smile tugged at the corner of his lips, a memory surfacing.
"Yeah. To explore the chemical and emotional patterns associated with affection." He gave a half-laugh. "A completely rational investigation into the absurdity of love."

You nodded, the corner of your mouth lifting. "And now?"

Senku looked down at the lapis lazuli rocket again, thumb brushing over its smooth surface. The flickering campfire reflected in his eyes, softening them.

"Now the data's messy," he admitted. "The variables keep changing. Emotional spikes I didn't account for. Hypotheses I didn't expect to form." He paused. "You weren't supposed to become my favorite part of the equation."

You felt your heart flutter—like the wings of a butterfly caught in a beaker. Controlled. Confined. Until now.

He looked at you then, and something unspoken passed between you.

"Maybe..." you said, voice careful but certain, "maybe we stop calling it an experiment."

Senku blinked, caught off guard. "You want to end it?"

"No." You shook your head, smiling gently. "I want to stop pretending it's just about the data. It's not a study anymore. It's us. It's... real."

He let out a breath, almost a laugh, but it wavered. "I don't know what I'm doing when it comes to this kind of stuff. Emotions. Attachment. Romance." His fingers squeezed yours a little tighter. "But I know I don't want to imagine the Kingdom of Science without you in it."

The quiet stretched again—comfortable now. Peaceful.

"You still owe me results," he added, lips twitching upward. "We said we'd document every stage of this behavioral process."

You raised an eyebrow. "Are you seriously turning this moment into another data point?"

He leaned in, just enough for his breath to tickle your cheek. "Only if you help me collect the data."

You laughed, the sound soft and breathless—and before you could talk yourself out of it, you leaned in too, resting your forehead lightly against his.

The moment hung between you like static before a summer storm. His gaze flickered down to your lips, just for a second—barely perceptible—and—

"OOOHHHHH~! My stars and science, am I interrupting something~?"

You both flinched as Gen's voice rang out like a dramatic stage cue. He strolled up with a grin as wide as the village, fanning himself with a handmade paper fan. "I knew I felt a spike in tension over here. Honestly, I thought you two were swapping samples!"

Senku groaned under his breath, already getting up to walk away, running a hand down his face. "Gen, I swear to Newton, if you don't walk away in the next five seconds—"

"Relax, relax! I'm just here to check on the lovebirds before we roll out. But hey, if you need me to officiate something later, I am ordained in the church of drama and pseudo-psychology~"

You covered your face, cheeks burning as you let out a helpless laugh. Senku just shook his head, smirking despite himself. "You are the worst."

Gen winked. "And yet, you love me anyway."