Detective Conan: I'm a Boy, But They Treat Me Like a Big Sister — Chapter 31

Chapter 31: I’ll Live Off This Secret for a Lifetime

Tōhō Getsukai smiled, reaching out to gently ruffle Ran’s hair.

“Okay.”

That single, soft syllable was all it took. The lingering annoyance tight on Ran’s face melted away. The sheer unpleasantness of being accosted by that perverted little brat earlier was entirely eclipsed by the faint, comforting scent clinging to Getsukai’s shoulder.

Taking the opening, Getsukai channeled a subtle pulse of Hamon Breathing through his fingertips, massaging Ran’s temples with practiced ease.

“Does that feel good?”

“Mmm…” Ran’s eyelids fluttered, heavy with sudden relief.

“You played all day, and then you had to deal with that nonsense. You must be exhausted.”

“A little…”

Getsukai withdrew his hands and stood up, smoothing out his clothes. “Come on. Let me take you home.”

The walk from Tropical Land back to the Mouri Detective Agency was a blur of quiet comfort. Ran practically melted against Getsukai’s side, her arms looped securely around his. The double-whammy of physical exhaustion and overwhelming security left her limbs feeling like jelly; every so often, she would tilt her head up to look at Getsukai, a silly, contented giggle escaping her lips.

By the time they reached the stairs beneath the agency, Ran was dragging her feet, pausing every two steps to look back.

“Sister Tōhō, aren’t you coming up to sit for a while?”

“No, I still have a few things to take care of.”

“Then get home safe, Sister. Send me a message when you arrive.”

“I will.”

Getsukai watched Ran disappear around the landing before pulling out his phone. He tapped open his photo gallery.

On the glowing screen, Shinichi Kudo writhed on the damp asphalt of a dark alley, his body convulsing as his skeletal structure visibly collapsed beneath his oversized clothes.

Getsukai’s thumb flicked to the next file. A pristine, high-definition video of the great high school detective reducing into a seven-year-old bean sprout. An exclusive masterpiece. The only copy in the world.

Smirking inwardly, Getsukai slipped the phone away and hailed a passing taxi.

“22 Beika Town, 2-chome.”

Dr. Agasa’s residence, right next door to the Kudo family home.

Given his uniquely close relationship with Aunt Yukiko, holiday visits were a staple, meaning the eccentric inventor had seen him around enough times. They weren’t exactly close friends, but the label of “that pretty child from Eri Kisaki’s family” was enough to get his foot in the door.

At that exact moment, the skies over Beika Town finally broke.

Heavy rain lashed against the pavement. A tiny boy swallowed by an adult’s blue jacket sprinted desperately beneath the flickering streetlights. Shinichi Kudo—or rather, a highly suspicious child of unknown origin—was soaked to the bone.

Home was just ahead. The two-story Kudo Residence loomed in the dark. Normally, he would just stroll up and push the door open. But his newly shrunken arms couldn’t even reach the doorknob, and his keys, along with his phone, had been abandoned in the mud of that theme park alley.

Left with zero alternatives, he dragged his waterlogged feet toward his neighbor’s house.

He crept up to the brick wall bordering Dr. Agasa’s garden. It was 1.8 meters high. Just hours ago, he could have vaulted it with one hand.

Now…

Shinichi gritted his teeth. He dug his tiny, trembling fingers into the wet mortar, kicked his oversized shoes against the brick seams, and hauled himself upward, his muscles screaming in protest.

With a pathetic thud, he tumbled over the edge and face-planted into the mud. He sat there, stunned by his own physical weakness, before forcing himself up. Stumbling like a drunkard, he aimed for the front door.

The lights were blazing. The Doctor was awake.

Shinichi slapped his palms against the doorknob and shoved with all his might.

“Doctor! Help—”

The plea died in his throat.

The living room was bathed in a warm, inviting yellow glow. Two cups of tea sat on the coffee table, ribbons of steam curling into the air. Dr. Agasa occupied the left side of the sofa, beaming cheerfully with a teacup in hand.

But it was the figure on the right that froze Shinichi’s blood.

Silver hair cascaded elegantly over a slender shoulder. One leg was crossed delicately over the other, the hem of a pristine skirt smoothed perfectly over their knees. Slender, pale fingers pinched the handle of a porcelain cup.

The figure paused mid-sip and looked up.

“Ah.” Getsukai flashed a deeply strange, amused smile at the muddy, shivering brat dripping onto the carpet. “You’re here?”

Shinichi jolted.

Tōhō Getsukai is here? Why is he here? When did he even arrive?!

Panic flared, but Shinichi ruthlessly suppressed it, slapping on the most innocent, wide-eyed expression a seven-year-old could muster.

“U-Uncle, it’s raining so hard outside, and I got lost! Could I borrow—”

“Shinichi, there’s no need to pretend.” Dr. Agasa lowered his tea, his expression a complicated mix of pity and awe.

Shinichi’s fake, childish smile shattered. He hadn’t even formulated a plan to convince the eccentric inventor of his identity, yet they had somehow skipped the entire verification phase?

“D-Doctor? How did you know—”

Agasa coughed into his fist, gesturing helplessly. “Tōhō recorded the entire process of you shrinking. I just finished watching it.”

“What?!”

Shinichi’s jaw unhinged. He stood paralyzed in the doorway, his blue lips trembling—whether from the freezing rain or sheer, unadulterated rage, he couldn’t tell.

Agasa hurriedly stood up, rummaging through a nearby cabinet before returning with a massive, fluffy bath towel. “Shinichi, dry yourself off before you catch a cold. Come sit down. Whatever this is, we can figure it out slowly.”

The Doctor draped the heavy towel over Shinichi’s shivering shoulders and guided him to the sofa.

Only when the thick cotton enveloped him did the absurdity of reality finally set in. He sat on the plush cushion, his two stubby legs dangling pathetically in the air, miles away from the floor.

Across the table, Getsukai sat with impeccable posture.

Shinichi gulped down a scalding mouthful of tea, then glared over the rim of his cup. “So, you were at the scene.”

Getsukai ignored the accusation, smoothly pivoting the conversation. “Kudo.”

“…What.”

“You wouldn’t want the fact that you’ve turned into a seven-year-old brat…” Getsukai’s flawless, girlish voice stretched out the syllables, dripping with a terrifying sweetness. “…to be found out by Ran, or by the whole school, right?”

Agasa’s hand froze halfway to his mouth.

Shinichi stiffened inside his towel, his fight-or-flight response redlining.

He knew Getsukai didn’t harbor any actual malicious intent, but the sheer trauma of being ruthlessly pranked by this “beautiful big sister” throughout his entire childhood hit him like a freight train.

If Ran found out he had shrunk?

Just an hour ago at the drink shop, he had been pinned to the floor, actively analyzing the scent of Getsukai’s Mary Janes, when Ran hoisted him up by the collar and beat the living daylights out of him. The label of “perverted shoe-fetishist elementary schooler” was permanently welded to his forehead.

If Ran discovered that perverted brat was actually him… he wouldn’t just be beaten half to death. He would be legally dead.

“I—I—” Shinichi practically threw half his body across the coffee table, plastering a sickeningly ingratiating smile onto his childish face.

“Sister Tōhō!” He had completely abandoned his pride.

“Think about—think about all the times I took the blame for you when we were kids!” Shinichi pressed his palms together in desperate prayer, his voice cracking. “Spare me!”

Getsukai remained silent, his expression so exquisitely bored it bordered on languid.

Taking the silence as a prompt to try harder, Shinichi began frantically airing out his lifelong grievances, desperate to prove his loyalty as a scapegoat.

“When I was five! My mom bought a limited-edition eyeshadow palette, you crushed the shades, and when she asked, I took the fall! She flicked my forehead for three days straight!”

“When I was seven! You knocked over my dad’s Meiji-era antique vase! I took the blame, and he canceled my entire summer allowance!”

“And—that time when I was eight! You used Mom’s expensive lipstick to draw on the walls—”

“Enough.” Getsukai raised a single, elegant hand, cutting off the tirade.

Shinichi snapped his mouth shut, staring back with huge, pleading eyes.

Inwardly, Getsukai was rolling his eyes hard enough to see his own brain. The only reason he had done any of that was because Aunt Yukiko found him ‘too pretty’and’too cute.’ She couldn’t resist pinching his cheeks, messing up his hair, and smothering him in suffocating hugs and kisses every time she visited.

Being young and physically unable to overpower Yukiko, he had refused to take the bullying lying down. So, he naturally redirected his vengeance toward the only Kudo family member he could actually bully: the son.

But they weren’t children anymore.

Getsukai had already decided it was time to upgrade his revenge plan and target Aunt Yukiko directly. Therefore, Shinichi Kudo was now a highly valuable tool.

Getsukai set his teacup down with a soft clink, folding his hands gracefully over his knees. “Fine. I can keep your secret.”

Hope exploded in Shinichi’s eyes.

“However, just keeping it a secret is terribly boring.” The slow, leisurely cadence of Getsukai’s maidenly voice carried a dark, playful amusement that sent a cold draft racing down Shinichi’s neck. “I think we should call Aunt Yukiko back to the country first.”

Shinichi blinked, stunned.

That’s it?

A massive breath of relief left his tiny lungs. Given the sheer magnitude of what had happened to his body, notifying his parents was standard procedure anyway. He had already planned to contact Yusaku and Yukiko in Los Angeles.

But then… he looked up.

He caught the subtle, chilling curve of Getsukai’s smile, and a deep sense of doom blossomed in his chest. Ever since they were in diapers, whenever Getsukai wore that exact smile, it was always the prelude to something that would make Shinichi’s life a living hell.