He'd be lying if he said it didn't throw him off guard the first time.
He'd also be lying if he said he was fully aware that Tantei-kun had his phone number.
And he'd be the worst liar in the world if he said he intentionally gave Tantei-kun his real phone number and not one for a burner phone and that it absolutely wasn't because he honest to god never would've thought that the WHOLE DETECTIVE CREW would be on one train while he was in the middle of a heist.
Kaito always enjoyed heists more when Tantei-kun was involved. It made them riskier and required more work than a regular heist, especially when Hakuba was involved too. Although Kaito had no desire to be captured; facing off against the two detectives was like a well-played game of chess with Stephen Hawking, as opposed to a game of chess played with a sixth grader. Even though he always managed to escape in the end, sometimes without his prize and by the skin of his teeth, he still enjoyed the chase and the thrill and the effort. After all, not many things can intellectually stimulate a seventeen-year-old with an IQ of 400. But sometimes his capture comes a little closer than Kaito would prefer.
Shoved between some filing cabinets in the museum curator's office is not a position Kaito ever wanted to be in. Hiding in plain sight doesn't bother him but hiding out of sight means something went wrong. First, there was the unexpected appearance of Tantei-kun; second, literally everything else. Nothing, especially his escape, went according to plan, all thanks to the pint-sized detective.
But, there between the file cabinets, he seemed to be temporarily safe from capture, giving him enough time to come up with a new plan. A new plan that consists of staying as quiet and hidden as possible because Tantei-kun just walked into the office.
At first, it was quiet. Kaito assumed it was because Tantei-kun was listening for him. Then, just as Kaito began to reach for a flash bomb to make his escape-
BRRRRRBRRRBRRRRRRRRRRRRBRRRRRRRRBRRRRRRRRR
The loud, metallic rumble of his phone in his pocket vibrating against the cabinet echoed from his spot.
What?!
He scrambled to silence his phone, not to stay hidden but to see whose ass he had to kick later for calling him during a heist. Upon glancing at the screen, however, he only saw a name:
CONAN EDOGAWA
"That would be me calling," Conan smirked and leveled his tranquilizer watch, "In case you never put me in your contacts."
Kaito quickly jumped out of the way of the dart and onto the file cabinets, crouching on top. "How did you get my number?!" Kaito yelled.
Conan grimaced, having wasted his only tranquilizer dart. "Does the Bell Tree Express bring back any memories?"
That's right! When I helped him save that girl!
"Are you kidding me? That's cheating!" Kaito yelled.
"Oh please, it's not cheating, it's just using my resources. I would never use it to track your location or anything. That would be cheating."
"That doesn't exactly make me feel any better. Anyway, I do you a favor, a life-saving one at that, and this is how you repay me? By using my kindness against me?"
"Shouldn't you know better than to keep your phone on during a heist?"
Kaito smirked, "If I kept my phone off, then how would my accomplice be able to tell me he's right outside the door?"
"What?!" Conan swiveled toward the door and Kaito used the opportunity to let off a flash bomb, blinding Conan and giving him a much-needed chance to escape.
When the temporary blindness wore off, Conan begrudgingly found Hakuba and Inspector Nakamori, who also admitted, begrudgingly, that they were also unable to catch KID. So, the task force and the two detectives begrudgingly left the museum to finish the residual paperwork, begrudgingly, and return home, begrudgingly.
It wasn't until Conan began getting ready for bed that he noticed the slip of paper in the pocket of his jacket.
Don't forget, Tantei-kun, you still owe me one.
Conan didn't even need to check the caricature in the corner to know who it was from.
Kaito was actually worried the second time. He had just arrived home after another successful heist, sans Tantei-kun or Hakuba, when he checked his phone for the first time that night and saw:
3 MISSED CALLS FROM CONAN EDOGAWA
Why was Tantei-kun trying to call me? Is he in trouble?
The calls were all within the last half hour. He looked at his voicemails. Nothing. His texts. Nothing. Kaito quickly dialed the little detective back. He picked up on the first ring.
"Finally, jeez," Conan answered, annoyed. Kaito was momentarily stunned.
"What do you mean 'jeez'?" Kaito yelled, angrily, "You called me three times I thought you were in trouble!"
"What? No. Why would I go to you if I was in trouble?" Conan scoffed.
"Didn't stop you on the train."
"Are you going to help or what?"
"Fine. What was so important that you had to call three times but couldn't leave a voicemail?"
"I need information for a murder case. Is it possible for someone to escape from a straitjacket underwater in less than a minute?"
Kaito was dumbfounded. "Um, I mean I could do it, but it would take some planning…"
"Okay so not at all possible then. Thanks bye."
"Wait a second! That makes two favors you know!"
The only response was the sound of Conan hanging up.
Kaito tossed his phone onto his bed. "I can't believe a six-year-old called me aboutmurder at two in the morning."
In retrospect, he probably deserved this one.
It was three twenty-seven in the morning and Kaito had finally fallen asleep after a very successful heist involving a very embarrassed Tantei-kun.
In the middle of an incredibly pleasant dream about a world without fish, he was rudely awakened by his ringtone that IS NOT NORMALLY THIS LOUD WHAT'S HAPPENING.
He scrambled to silence his phone as quickly as possible and when he finally got it to "shut up please stop oh my god" and was no longer staring into the blinding luminosity of the call screen, he noticed that the culprit was none other than Tantei-kun himself.
Kaito briefly debated ignoring what he knew was revenge, but instead decided to bite the bullet and call him back. When he picked up on the first ring Kaito's suspicions were confirmed.
"Oh, hey there Kid," Kaito could practically hear the smirk on his face. "I didn't think you would pick up. After all, it's not like you keep your ringtone on high while you sleep, right?"
"I'm not afraid to hit a six-year-old."
"And I'm not afraid of giving your number to every member of the task force."
"Aw, you wouldn't actually do something like that. Especially since you looked so cute in your outfit tonight."
"I'm calling Hakuba."
"Wait! Okay, I'm sorry. I'll delete all the pictures I took from my phone."
"I already did that for you, but I appreciate the gesture."
"So, we're even and you won't expose my number to the world?"
"You owe me a favor now."
"Actually, that just means you owe me one less," Kaito explained, but Conan had already hung up.
I'm not a murderer, but I'm gonna murder this kid.
Another night, another late-night phone call. Only this time, Conan didn't answer when he called back. At first, he assumed it was a mistake because Conan didn't try to call back. Kaito laid back down and, about ten minutes later, was just starting to fall back asleep when Conan called again.
Annoyed, Kaito answered his phone, only for Conan to hang up on him.
What the hell?!
Kaito was starting to worry a little. Maybe the kid was in trouble and couldn't speak so he was trying to send him a message? If Conan couldn't pick up, then maybe he should just wait for his next call.
Kaito sat up in bed and waited, expecting the next call to come any minute. What he wasn't expecting, was for the call to come almost ten minutes later, again.
There were two possible scenarios, Conan really was in trouble and was trying to send him a code, or he was just dicking around. There was only one way to know for sure. Kaito tried calling Conan back one more time and, when he didn't pick up, Kaito waited.
Sure enough, ten minutes later Conan called again.
Alright, brat. Two can play at this game.
Instead of trying to call Conan again, Kaito called the Mouri Detective Agency.
As he expected, no one picked up on the first ring. So, he waited ten minutes.
On the second try, he let the phone ring twice before hanging up.
On the third try, someone finally picked up. Kaito was fully expecting it to be Detective Mouri or Ran, so he was pleasantly surprised when a childlike voice rushed through the phone, "Okay, okay, I give up! Please stop calling, you're going to wake everyone up!"
"I'm going to wake people up? Listen here pipsqueak, you call me one more time in the middle of the night for a non-emergency and I'll make your phone bill hit the sun!"
"Okay, I get the message jeez!"
"Again with the 'jeez' like this is my fault! The next time I see you we're gonna have a talk about the appropriate uses of a thief's phone number. And don't think I'm not adding on another favor!" But as he said it, Kaito's voice had a softness to it.
But Kaito understood some of what was happening, so when Conan called his bluff and kept him up for four hours doing the same hang-up trick again a week later, Kaito didn't mention it. And one month and twenty-two favors later, Kaito and Conan's late-night conversations weren't as obnoxious as they'd once been, or as one-sided. The two geniuses had a silent agreement to never speak about what was said over the phone, or that the phone calls happened in the first place, and they would never share to each other the secrets that plagued them.
Until those secrets revealed themselves.