In hindsight, Shinichi realizes that his (re)introduction to Kuroba Kaito was something like love at first sight.
There was a time when Shinichi didn't share his room with Kaito. It was just him, Hattori, and Hakuba in an expensive apartment that they rented together with the help of their very generous parents. He had a queen-sized bed, a desk, and a nightstand stacked with case files which he had more often than not been going through until at least 3:00 A.M. He would get up after 3, maybe 4 hours of sleep to go to classes and solve the murder of whatever corpse had fallen on his head that day. The other two detectives had similar schedules, so naturally, the girls avoided their hellhole of an apartment like the plague.
He hardly ever ate a proper meal and had lost an unhealthy amount of weight and fell asleep in every class he took. His depression's probably gotten worse, too, given his increased irritability and hopeless outlook on life (to be fair, taking down the Black Organization had left him a shell of a man- or boy?). Hakuba and Hattori had done more botched intervention attempts which ended in them bickering than he could count. And every time they meet, Ran looks at him with a sad look in her eye usually reserved for victims and the Detective Boys asking about Conan. He'd always say he's fine though because he knew that things could've been worse.
But Shinichi counts his blessings every day. For one thing, he's not a child anymore. For another, he doesn't live alone anymore. And now, he's got Kaito.
He had met Kuroba Kaito through Nakamori Aoko, Ran's roommate. It took them under a minute to deduce each other's (former) alter egos. It took them just another to agree that this never comes up again.
Around the same time Kaito reentered his life, Shinichi watched the self-hatred and cynicism slowly begin to leak out of his life. Every morning, Kaito let himself into the apartment and made breakfast and coffee for the detective (he didn't have a key). He also became Shinichi's "study partner", which meant that they would pester each other until midnight when Kaito would have to wrestle case files out of the detective's hands and force him to go to sleep before 12:30 A.M.
More often than not, Kaito ended up falling asleep before Shinichi. As a good friend, he just offered the magician a drawer to put some clothes in.
Hakuba and Hattori initially took issue with the newcomer. The other two detectives were suspicious of the sudden disappearance of their collected grocery money. Now, neither of them would ever admit it, but Shinichi knew they were glad that Kaito was around when Hakuba would meal prep for the week and Hattori would make fun of him while eating a bag of potato chips.
It was also the magician who mandated biweekly cleaning events throughout the apartment, where the roommates were forced to "clean your goddamn house to keep the rats out" while giving the most demanding tasks to Hakuba for the sole purpose of watching him suffer. Amidst the various obscenities muttered throughout the process, the detectives' apartment slowly became a livable place to be. Kaito was upgraded from welcome guest to honorary roommate when furniture which he and Shinichi bought on a day out together had made Aoko's jaw drop and rendered Ran speechless for several moments.
He basically lived there anyways, so when Kaito showed up at their door after a day of uncharacteristic silence with the news that he had been evicted from his apartment for one too many hazardous magic tricks, Shinichi didn't hesitate to let him in.
Typically, they would wake up on other sides of the bed.
Today is different. Kaito and Shinichi's comforter is on the ground for some reason but he's still warm, which shouldn't be the case in the middle of November. Shinichi tries to crawl out of bed, but he's restrained by something wrapped around his chest and a following groan and sniffle. Not something, but someone.
"Kaito, get off of me," he orders, not unkindly. The other boy squeezes Shinichi harder and mutters, "Save me."
Sleep-talking. Shinichi humors him. "From what?"
"Th-the f-fin-ny thing-s," Kaito whimpers.
Shinichi sighs. He can't see Kaito because of the position he's being held in, but he's certain that the magician's half-open eyes have tears spilling out of them. He settles back down since it's clear that he can't get up anyway.
"I suppose my criminology professor won't miss me for a day," Shinichi says with faked passive-aggressiveness. Kaito grumbles "Yay" and something else, but before he can ask what, the magician was already pretending to sleep.
There's no point in trying to "wake" the magician. Shinichi laid there, thankful for Kaito's body heat because he couldn't reach their blanket. Kaito pulls him in even closer until the two of them are pressed up against each other nearly everywhere. Their feet are intertwined in a tangled mess and Kaito's nose is tucked under Shinichi's head, leaving him with a sole cold point thankfully muted due to his hair. If he wasn't my friend, then I would be panicking right now.
As a detective, he observed how he was struggling to relax his body because Kaito's lips were pressed against the nape of his neck, blowing warm air onto him in a calming rhythm. His mind wouldn't stop moving, wondering how those lips would feel elsewhere.
Well, when you're wondering about your best friend's lips, there's only one thing to do.
"What are Kaito's lips like?"
"Why the hell are ya askin' me?"
"Well, I was hanging out with Kaito the other night and for some reason starting wondering about his lips…? And I've never been close enough to him, uh, like that, but you did during that heist-"
"…why dontcha just find out yourself? Such a great detective should be able to find such a simple answer."
That evening, Shinichi and Kaito were sitting on a grey loveseat in the apartment's newly furnished living room. More specifically, Shinichi was sitting on the couch rereading The Sign of Four when Kaito had sauntered over and draped himself across the seat and consequently the detective's lap. Between the stupid faces that Kaito was making and the presence of those perplexing lips, Shinichi had only gotten through two pages of his book before the magician snatches the book out of his hands.
"Hey, I was reading that!"
"No you weren't, it's been an hour and you've only gotten through two pages. Usually, you only look up if I make something burn, which is like once every other hour." Shinichi's brow furrows for a moment as he checks his phone. Kaito is terrifyingly accurate.
His now free hands cup Kaito's cheeks. He twists his back to lean down to Kaito's face further, where he has a better view of his lips. Full, pink, and slightly cracked, presumably from the cold weather…
It takes him a moment to remember where he is. "Aww, KID-sama, do you take pleasure in stalking my behavior?"
"What? No, I, uhhh… you were looking at me first! Is something wrong?"
Kaito's bright red and his poker face is demolished. Shinichi knew that if he asked "What are your lips like?" right now, then he would get an answer right away. The only problem would be that his best friend would likely never let him live it down. He lets go of Kaito's cheeks and stretches enough to crack his back several times. His eyes are trained to the ceiling.
"Nothing," Shinichi responds with a teasing lilt to his voice. It doesn't occur to him how much they've taken on much of each other's personalities until he risks a glance at a grumbling Kaito who has covered his face with irritation. He actually feels kind of bad, so Shinichi moves his hand to run through his friend's hair in the rhythmic way he always likes. They remain like that for a couple more minutes until Kaito suddenly sits up, properly seats himself on Shinichi's lap, and slides his hands dangerously close to the waistband of the detective's pants.
This time, it's Shinichi's turn to flush red. "Is Hattori watching us again?"
"It's in his blood as a detective. I'm just giving the audience what they want, Don't worry, I anticipate us getting revenge soon," Kaito smirks, nuzzling his neck with his fluffed up hair.
Shinichi rolls his eyes. It always confused him why the audience would want him and Kaito to be so intimate. They're just friends, after all.
But at least he would get something out of it. Something Kaito had said gave him a new angle to approach the original problem.
"What I mean is, you'll have the allele sequences, but I doubt you'll be satisfied with your findings. How are you supposed to reconstruct his lips?"
"I should've thought of that,"
"You know, you should go on a more personal route to find the answer to your questions. Kuroba-kun is your frie- I mean, uh, not a suspect. You have more direct methods to be doing this."
…
"Kudou-kun is having a crisis that's not my fault. Spend some time together tonight and try to make him feel better. He's about 10 minutes away since he was just in the library."
The first thing Shinichi does when he gets back to the apartment is replace his pants with a pair of sweatpants Kaito had bought during one of his long-distance KID escapades. The second thing he does is launch himself onto his bed with a cathartic grunt. He remains there, wallowing in his misery and wondering what Kaito's lips are like.
"Shit," he breathes. Where is Kaito, anyway? Didn't Hakuba say he'd be here?
"Are you thinking about me?"
This time, Shinichi screams "Shit!" as he rolls over on the mattress too quickly. He falls off the bed with a thud. Kaito's looking down at him and struggling to stifle a laugh. Shinichi resolves to lie on the ground instead of climbing back onto the bed.
"You get 5 seconds to laugh at me."
The next seconds are some of the most degrading his entire life (and that includes being shrunk into a child). Kaito snorts, actually snorts, as he doubled over in his contagious cackle. It definitely takes longer than 5 seconds, but Shinichi eventually joins in because Kaito makes everything better.
Friends definitely make everything better.
Eventually, Kaito throws Shinichi on the bed and leaves the room, making him promise to not move an inch. When he comes back, he's holding two bowls, the ones that Kaito normally uses for ice cream. Shinichi rolls his eyes.
"Kaito, just because ice cream makes you feel better doesn't mean it's the solution for my problems too."
Kaito ignores him, holding out a bowl. "This one's yours. Just try it. I know you'll love it."
It looks like ice cream, but not the one that Kaito's eating with him. It's melting faster, and is also somewhat transparent…
Kaito lets out an exasperated sigh and places his own bowl on his nightstand. "Stop being a detective and just eat it," he exclaims.
Before he can react, Kaito shoves a spoonful of bitter, cold, and lemony sweetness into Shinichi's mouth…
… and it's fucking fantastic.
He swats Kaito's hand from the spoon. As he scoops more of it from the bowl, he looks over at his proud friend and asks, "What is this? It's amazing!"
Kaito laughs. "It's lemon sorbet. For some reason, your taste buds crave bitter sweets like lemon pie, and I assumed that this is probably similar to it. I knew you'd like it," he responds, puffing out his chest.
The slight way his shoulders relaxed when Shinichi had reacted indicates otherwise, but he chose not to say anything. "You know me so well. I don't deserve friends like you…"
For a moment, Kaito's face falls. He does his best to cover it up by picking up his own ice cream, but it leaves Shinichi wondering what he had said.
They finish their respective sweets in uncomfortable silence. Shinichi wants to say something, but he's not sure what.
When Kaito leaves the room again, he doesn't say anything to the detective. The cool nature of his friend drives him insane. While waiting for the other boy to come back, Shinichi paces, rehearsing an apology for anything he had said.
Of course, amidst his pacing, he runs into Kaito who steadies him before he topples over. Before he knows it, Shinichi is trapped under the magician's firm grip on either shoulder. Kaito's eyes are unnaturally intense and searching, and Shinichi is entranced. His lips part in anticipation of something, but before he can place what exactly, he's pulled into a strong embrace.
"You deserve the world, Kudou Shinichi. Just ask for it and I'll bring it to you," Kaito vows in a hushed tone. Kaito turns his head towards Shinichi's neck and nestles his head there. Shinichi shifts his own down, closing his eyes from the intensity of the moment.
He would've asked then, about Kaito's, but Shinichi's body wouldn't cooperate with his brain. His nose was buried into Kaito's chest, and the combination of his smokey scent and firm chest left his knees weak.
Kaito spent the rest of the night continuing to read The Sign of Four to Shinichi, who laid sleepily on his side facing the magician. He couldn't help but be captivated by the former KID's smooth voice, even as it became raspy.
Shinichi must've drifted off at some point because the next thing he knows, the room is dark and his arm has fallen asleep. Groggily, he notices that the lights are on outside of his room, and his three roommates are talking in the hallway. He lies on his back and strains his ears to no avail. The clock next to him says 1:00 A.M. It's past our bedtime.
"Kaiiiiii," Shinichi groans, trying to get the magician's attention but too tired to say the whole name.
He's pretty sure Kaito didn't hear him, so Shinichi pulls the comforter to his chin and closes his eyes. Gradually, his eyelids become heavier and his breathing becomes even.
By the time Kaito returns, Shinichi is shocked he's still conscious. Through a sleepy haze, he feels something warm press against his cheek. It leaves electricity and intense spreading through his entire body, causing Shinichi to squirm.
Kaito's chuckles breathily, unlike his cackle from the beginning of their night together. He runs his hands through the detective's hair the same way he likes it. When he reminds Shinichi that "I get to call you a nickname now," even though he's supposedly asleep, everything clicks together.
I don't think I want to just be friends with Kaito.
"…how do you know I… I love him?"
"Trust me, I think you knew before the rest of us."
I love him.
I love him.
I love him.
That's all he can think about when Kaito gets him his phone back.
That's all he can think about when he promises to defend Kaito from Masumi.
That's all he can think about when Kaito calls him Shin-chan for the first time and he hardly tries to stop him.
He's missed the signs before, but now they refuse to go away. He's definitely in love with Kaito, and he's certain that he has for a long time. But more importantly, he's got a foolproof method to unearth the mysteries behind the magician's lips.
As usual, Shinichi is in his room, pretending to pore over case files while actually staring out the window and thinking about Kaito. He's with Aoko right now, presumably back at the girl's apartment doing whatever they did. But the house actually smells like homemade food, indicating that the girls are over. So he's… here?
He stands up to go check the living room for him, but as he's standing up, their door opens and Aoko throws Kaito into their room. He looks ready to bolt, but Aoko calls out "Figure your shit out!" and his hand slides away from the handle.
He turns around and Shinichi takes him in. Tall, built, a face with intense violet eyes and unruly hair. He unconsciously licks his lips, and Kaito's eyebrows raise.
"Can I help you, Shinichi? You've been acting off all day."
Shinichi looks up with determined eyes. "I'm going to kiss you."
There's hardly a moment between Kaito saying "Okay," and Shinichi running and jumping into his arms. Shinichi wraps his legs around him and his breathing hitches, painfully aware of just how close he is to finding the answer to his question. Kaito stumbles back against the door and lets out a brief gasp from shock, but he leans forward and closes the gap between the two.
Kaito's lips are soft and surprisingly glossy. Chapstick, Shinichi deduces as he licks the cherry taste from them. Kaito is surprisingly passive during their kiss, letting the detective cradle his head and tilt it up. Shinichi coaxes his tongue into his mouth, and Kaito lets out a small moan which only excites him further as he lets his arms slide behind the magician's neck and then down to his chest.
When Kaito pulls away, they're both panting and flushed. Between breaths, Kaito smiles sheepishly and mutters, "I have to let you down now."
Shinichi takes a step back but refuses to let go of Kaito's hand. He smiles softly and looks into the magician's eyes that have replaced their intensity with pure softness and fondness.
"I love you. Shit, I probably should have mentioned that before, but I-"
Kaito cuts him off with a chaste kiss which just brushes his lips. When he steps back again, his free hand cradles Shinichi's face and gently brushes his cheek with its thumb.
"I've known. I've loved you since we were reunited at that part. I knew you did too, but understood that you had to come to the decision on your own."
Shinichi furrows his eyebrows and gently palms the Kaito's hand on his face. "How could you know for that long?"
Kaito's grin is familiar. "I am a rather intuitive person, Tantei-kun. Now," he pushes Shinichi against their shared dresser, "You've had your fun. Why don't we get that long-awaited revenge on our roommate?"
Shinichi smirks and makes sure to moan as loudly as possible when Kaito's lips meet his lips again.
"They are so fucking loud. I will never know peace again, ya hear me?"
"Were you guys planning all of this out?"
"Lay off of my boyfriend."
"To us."
By 12:45 A.M, Shinichi had fallen on Kaito's chest and was breathing constantly against his skin. Kaito pulled him into a tight embrace. Shinichi stirred, only muttering something along the lines of "you smell good" before going back to sleep. Kaito smiled, muttering "I love you" one more time to the detective before closing his eyes.
He had waited so long to say it and internally vowed to never miss an opportunity to remind Shinichi.