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The smell of warm cocoa and vanilla wafted through the Kingdom of Science like a siren call. It drew a few curious heads—Ginro sniffed the air from across the field and almost wept—but none were quicker on their feet than Kohaku, her spear slung lazily across her back as she stepped into the lab, eyes narrowing.
"You've been in here for hours. What are you doing now, Senku?"
"Isn't it obvious?" he said, grinning like a madman from behind the distillation rig. “We're advancing civilization one sugary chemical process at a time.”
Kohaku tilted her head.
“…So. Chocolate again?”
“Plus ultra,” Senku said, dramatically sweeping his arm toward the table beside him.
There, lined up on a leaf-lined tray like a primitive product display, were rows of thin biscuit sticks, each dipped halfway in either shiny dark brown chocolate or pastel pink strawberry coating. A few were slightly crooked. One had snapped in half, likely from an earlier miscalculation. But most of them looked, well…
“Cute,” Kohaku muttered.
Senku froze mid-sentence, halfway into an explanation about tempering temperatures and sugar bloom.
“…Cute? You? Saying something's cute?”
She ignored him and reached for one. “Are they edible?”
He raised a brow. “I wouldn’t waste my precious cacao reserves on aesthetic alone, thank you very much.”
That was all the permission she needed. She picked up a chocolate one, sniffed it once like she expected it to bite back, then crunched down.
Her entire expression changed.
“…!”
Senku smirked and turned back to his notes.
“It’s a biscuit-based snack stick,” he rattled off, “mass-produced with precision molding during the pre-petrification era. The coating process was simple enough to recreate with some heated chocolate and—”
She grabbed another. Strawberry this time.
“I didn’t have freeze-dried strawberries or commercial flavoring, obviously, but I did manage a basic infusion using—”
Kohaku’s eyes fluttered shut as she bit down again.
“…Infusing dried berries into fat?” she asked between chews. “Isn’t that dangerous?”
“Not when you know what you're doing,” he said, puffing out his chest just a bit. “Which, you know. I always do.”
She didn't answer. She was too busy devouring stick number three.
Senku tapped his chin and watched her. Even now, her movements were efficient, sharp, fast. Like she was training her taste buds the same way she trained her muscles. If there were a snack speed-eating competition, Kohaku would probably cleave through the competition without breaking a sweat.
She licked a smudge of chocolate from her thumb. “You said this was a common snack before the world ended?”
“Yep. And people used to treat it like candy, but also like a weird excuse for… I dunno. Flirting? I think?”
She blinked. “Flirting?”
And there it was: that flicker of curiosity in her azure-eyes.
Senku leaned back against the workbench and let a slow smirk crawl across his face.
“Yeah. There was a game. The Pocky Game, they called it.”
“…What kind of game?”
He snapped one of the longer sticks in half and tossed it to her. “One person bites one end. The other person bites the other. First to pull away loses.”
She blinked again. “That’s it?”
“Well. Not exactly.” He gestured vaguely. “The point was to see who could get the closest to the other person without chickening out.”
Kohaku squinted.
“…So it’s just a staring contest with snacks.”
He snorted. “I mean. Technically, yes. With a risk of lip collision.”
A pause.
Kohaku’s brows furrowed. She stared down at the stick in her hand. Then at him.
Then slowly, slowly—
“…Senku. Are you proposing we battle using snack sticks?”
His grin widened like a cat with a laser pointer.
“Oh, I absolutely am.”
Kohaku stood across from Senku with the Pocky stick between her fingers like a sword. She had an eyebrow raised, expression totally unreadable save for the faint twitch of amusement at the corner of her mouth.
“Alright,” she said, squinting at the chocolate-dipped snack. “You bite one end. I bite the other. And then we keep going until one of us backs off.”
“Or,” Senku clarified, holding up a finger, “until someone chickens out and loses. Meaning, this is a game of psychological warfare. Reflex control. Lip trajectory analysis. Coordination.”
“…You are trying way too hard to make this sound like a scientific experiment.”
“Because it is,” Senku declared, already running a finger down an imaginary axis in the air. “There’s a statistically optimal angle for approaching, a balance of force and restraint—if I account for mandibular alignment and distance ratio, I can guarantee I’ll—”
Crunch.
She was already biting the stick.
“Hey.”
Kohaku, half a step forward and already halfway through her end, tilted her head. “What? We’re playing, aren’t we?”
“We haven’t even—! Tch. Whatever. Fine.” Senku reluctantly leaned in, biting down on his side with precision and caution. “Just don’t lunge like a wild—“
Too late.
In true Kohaku fashion, she went straight for the attack. No feint, no warning, no pacing. Just full-force, face-forward, and before Senku could calculate a countermeasure—
WHACK.
Lips smashed. Nose bumped. One of them probably got a chocolate smear somewhere on their face and the Pocky stick snapped in the middle with a pathetic crunch.
Senku recoiled with a strangled grunt, clutching his mouth.
“OW—!! What the hell was that?!”
Kohaku blinked, surprised. She rubbed her chin. “Did I win?”
“You didn’t win, you crashed into me!”
“Well, you said the goal was to not back off. I didn’t back off.”
Senku let out a pained hiss, still pressing two fingers to his lower lip. “That wasn’t a win, that was a headbutt with flavor. I think you chipped my incisor!”
Kohaku snorted.
“Unbelievable,” Senku muttered, staring mournfully at the ruined remnants of the stick on the floor. “The most unscientific approach imaginable. No rhythm, no strategy, just brute mouth-force.”
She looked proud. “Didn’t say I couldn’t use warrior instincts.”
He shot her a glare. “That wasn’t a kiss, by the way. In case your caveman brain is confused about the difference. That was a blunt-force trauma incident.”
“…Was it supposed to be a kiss?”
“Of course not!” Senku’s jaw clenched. A faint pink climbed his ears. “It’s a game. Not a confession ritual.”
Kohaku crossed her arms, not even pretending to hide her grin now. “You sound disappointed.”
“I’m injured, not disappointed!” he snapped.
A pause.
Then, as if granting him mercy, Kohaku plucked another strawberry Pocky stick from the tray and held it between two fingers, offering it out like a weapon across the table.
“Want to go again? You can explain the rules properly this time.”
Senku narrowed his eyes. Then sighed through his nose.
“Ten billion percent,” he muttered, “I am not losing to a snack-speed berserker twice in a row.”
Senku snatched the Pocky stick from Kohaku’s hand with the grumpiest precision imaginable. Chocolate side up. Flawless alignment.
Zero margin of error.
He pointed the stick at her like a conducting baton, brow furrowed with scholarly vengeance.
“Okay. Let’s try this again—correctly—since someone decided to treat the Pocky Game like a wild boar charge.”
Kohaku shrugged, utterly unrepentant. “I thought it was fun.”
“Well, my face didn’t. I think I bruised my maxilla.”
“Is that like the mouthbone?”
“Yes. And no, that’s not what it’s called. Anyway—”
Senku held the Pocky stick up between them, angling it carefully.
“Here are the rules. Again. Slowly. For your anti-subtlety brain. One person bites one end. The other bites the other. You inch forward, bit by bit, and the first person to pull away loses. No ramming, no sudden movement, no full-face tackles. This is a game of gradual escalation. A battle of nerves.”
Kohaku squinted. “So we don’t try to win quickly?”
“Correct. In fact, speed decreases the tension. It’s like chess. But for your lips.”
“…Dunno what chess is, but alright.”
Senku exhaled through his nose. His eyes sharpened with focus.
“And I’m going first this time. Watch carefully—this is how a rational person initiates.”
“Right... Scientific demonstration,” Kohaku said with a little amused bow of her head.
He stepped forward, holding the Pocky horizontally between his fingers. Then, very deliberately, he bent down and placed one end between his teeth with immaculate precision. No bending. No cracking. Not even a twitch of misalignment.
He straightened and looked at her.
“See? Proper. No chaos. This is the optimal starting distance—enough to initiate the challenge, but not so far it turns into a fencing match.”
Kohaku tilted her head. “So now I’m supposed to bite the other end?”
Senku nodded—carefully. “Correct. And once we’re both in place, we advance. Gradually. And—!”
Too late.
Kohaku leaned in with the same nonchalance as someone reaching for a snack at a picnic and clamped down on the other end before he could finish.
Senku froze.
“…Seriously?”
“What?” she mumbled, voice slightly muffled through the stick. “I did it right this time.”
He narrowed his eyes. “You didn’t even pause for dramatic tension—!”
She looked very, very smug.
Senku clenched his jaw and stared directly into her eyes.
“Fine,” he muttered through the stick. “Now the test begins.”
One millimeter at a time.
Slowly. Precisely. Like compressing a spring under exact pressure.
Ten billion percent he would win.
Unless, of course…
Senku’s teeth gripped the Pocky stick like it was holding together his pride, his dignity, and the last barrier between him and total psychological collapse.
Opposite him, Kohaku was annoyingly calm. Her expression neutral. Relaxed. Even playful. She looked like she was holding back laughter, and Senku hated—hated—how much it threw off his internal calculation models.
His brain fired off like a supercomputer gone haywire.
Distance between lips: ~4.2 centimeters.
Kohaku’s current bite angle: 38 degrees, too relaxed.
Air pressure? Humidity? Her eyes??
Focus, dammit. Focus.
He advanced. One bite forward. The stick shortened by maybe a centimeter.
Kohaku mirrored him with zero hesitation. Chomp. Smirk.
Senku’s eye twitched. “You’re supposed to hesitate.”
Through her end of the stick, she murmured, “Why would I?”
Another bite. She was so close now he could count the flecks of blue in her irises.
Senku didn’t move.
Not because he was backing out. No. He was recalculating. Adjusting his strategy. Reanalyzing the game.
(Definitely not because Kohaku’s breath was warm against his mouth and his brain was going absolutely haywire trying to ignore it.)
He took another tiny bite.
So did she.
Now? They were less than a centimeter apart. Pocky barely holding together. No room to calculate. No time to retreat.
Senku’s voice was taut. “If you break formation again, I swear—”
Snap.
The last fragment of Pocky gave out under both their bites.
And suddenly—lips.
Not a kiss.
No. A collision.
A soft, stupid, accidental collision of two people’s mouths who definitely weren’t expecting contact but absolutely just got it.
Senku flinched backward like he’d been struck by lightning.
“OW—GOD—!”
Kohaku blinked, slightly cross-eyed from proximity. “…Huh.”
He pressed a hand over his mouth. “AGAIN?! I specifically outlined the ideal distance-to-bite ratio! I timed my movements—!”
“You slowed down,” she pointed out, coolly wiping chocolate off the corner of her lip. “Maybe your math’s just bad.”
“MY MATH IS NEVER BAD.”
“Well, then maybe your focus is,” she said, arms crossing. Her tone was teasing, but her cheeks had a faint pink to them. “You got all weird once we got close.”
“I wasn’t weird,” he snapped, still hiding behind his hand. “I was calculating how best to avoid full contact.”
“You failed.”
“I noticed.”
A silence.
Then—
“…Are you mad because I won again?” Kohaku asked, voice syrupy with mischief.
Senku dropped his hand slowly. His face was flushed, but not just from embarrassment.
“I’m mad,” he muttered, glaring at her with deeply scientific spite, “because I got scammed out of a kiss and assaulted at the same time.”
Kohaku tilted her head. “So you did want a kiss.”
He scoffed, turning sharply to hide the deeper flush crawling up his neck.
“Shut up and eat your dumb stick, muscle-head.”
She grinned.
“…You gonna try again? Third time’s the charm?”
He paused.
Then, very slowly, picked up another strawberry Pocky.
Held it out.
“…Ten billion percent, this time? I’m landing it perfectly.”
Kohaku’s smile widened.
“Then get ready to lose again, science boy.”
They stood at the bench again.
This time, the air between them wasn’t just charged with mischief and snack-based rivalry. It was quieter. Thicker. Like the silence you get just before a thunderclap—when the clouds haven’t moved but somehow, you know something’s about to shift.
Senku didn’t speak right away. Just rolled the Pocky stick between his fingers, eyes narrowed. Calculating. Not like before—less about geometry, more about something he couldn’t quite quantify.
Across from him, Kohaku leaned against the table with her arms folded, watching him.
And waiting.
No teasing.
No grin.
Just that steady, unreadable look she got when she was sizing up something dangerous or important.
It made something flicker in his chest.
“…Okay,” Senku said, voice low. “One more time.”
She nodded once.
He didn’t narrate this round. Didn’t list rules or angles or formulas. Just raised the stick between them and bit down on his end. No dramatics. No smirk.
He waited.
Kohaku stepped in and mirrored him, barely brushing his hand as she aligned herself. A quiet, unintentional contact.
Their eyes locked.
Then—
Crunch.
One bite forward.
And another.
It was slower this time. Not clumsy like the first round. Not aggressive like the second.
Just…tense. Quiet. Electric.
Senku was aware of everything. The shift of Kohaku’s shoulders as she leaned in. The faint, uneven sound of her breath. The way her eyes didn’t flick away once.
He matched her pace, heartbeat accelerating with every millimeter lost to the stick. There were maybe three centimeters left now. Maybe two.
He stopped.
She didn’t.
A whisper of chocolate broke off between them.
Their mouths were close—closer than any of the previous rounds. And this time?
Neither of them looked away.
Senku felt his brain scramble. Not in the way it usually did when plans broke down. Not even like panic. More like—
Is this happening?
He should’ve pulled back. It would’ve been the dignified thing to do. The scientific thing. End the game. Reassert dominance. Lecture her about impulse control.
Instead—
He cheated.
Barely. Subtly.
Tilted his head just enough. Moved a breath sooner than the stick demanded. Closed the distance by one fraction of a second—
And kissed her.
A real kiss. No lip-bump. No snack collision. Just the warm, quiet pressure of his mouth against hers, deliberate and tentative and somehow…not tentative at all.
Kohaku froze.
But she didn’t pull away.
And that—not the kiss itself, but that—was what sent Senku’s internal equilibrium completely off the rails.
After a beat, he pulled back just slightly, barely enough to speak.
“…That,” he said, voice low and a little hoarse, “was ten billion percent not in the rules.”
She blinked at him, pupils wide, like she hadn’t fully registered it yet.
Then—very quietly—
“…You cheated.”
His lips curved upward. Not a smirk. Not gloating.
Something else.
“Yeah.”
A pause.
“Was it good?” she asked, dead serious.
Senku coughed once. Looked away. “Scientifically speaking… inconclusive. Might require repeat testing.”
Kohaku tilted her head slowly. “Same conditions?”
He met her gaze again. His heart was pounding. She probably heard it.
“…Maybe with fewer snack-based obstacles.”
She leaned in a fraction. “That’s not very scientific of you.”
“Yeah, well.” He licked his lips, still faintly tasting strawberry. “Not everything needs a data table.”
Another pause. A heartbeat.
“…I’m not gonna pretend that wasn’t good,” she said simply.
Senku’s brows twitched upward—but before he could come up with a response, Kohaku straightened up, snatched another Pocky stick from the tray, and chomped it clean in one go like nothing happened.
Then she turned toward the door.
“Break’s over. Don’t blow up the lab.”
And with that—just a flicker of a glance over her shoulder—she was gone.
Senku stood there for a long moment.
Staring at the door.
Then back down at the tray.
And muttered to himself, low and dry:
“…Ten billion percent worth the concussion.”