Seikuza Masaru was relatively new to the Kaitou KID Task Force, having only four heists under his belt after being transferred six months previously. He learned quickly, both from experience and from his coworkers, that there were four things you needed to know to get through multiple consecutive heists with your mind intact.
One, Nakamori-keibu was in charge, but you should take some things he said with a grain of salt. Two, Kaitou KID was absolutely fucking insane so you should be prepared for and/or expect anything. Three, despite his age and rather irritating demeanor, Hakuba Saguru was damn smart and should be listened to (most of the time). And finally, Edogawa Conan was fucking creepy.
The kid (because he was seven, even though he looked about five) had come the closest to catching KID of anyone, which prompted a lot of puns about how it took a kid to catch KID, and more than a few drinks.
Masaru himself had never met the boy in person, but he'd heard stories and read the newspapers and was kind of interested, if only because Edogawa-kun must have been very smart to be able to corner KID so many times when Nakamori-keibu had been at it for over a decade and had barely ever come close to catching the thief without outside help.
He'd never imagined the stories some of the other officers had told him about the boy were true.
It was several weeks after the heist in Osaka that everyone avoided talking about in specifics, both because Hattori Heiji was frightening and because his father was a police chief and could probably make their lives miserable even if they were in a totally different city's police force. Suzuki Jirokichi had once again called KID out, this time a gold ring with a magnificent emerald everyone spent an appropriate time "ooh"ing and "aah"ing over.
Suzuki-san had insisted on wearing the ring himself as part of his plan to catch KID, but as it was a bit too small for him to wear on his finger, he wore it on a thick cord around his neck.
At the time Kaitou KID had promised to arrive, the thief appeared right beside Suzuki-san, a cocky smirk on his face.
"Get him!" Nakamori-keibu shouted and Masaru and those of his colleagues who'd been hand picked for this heist ended up in a pile on the floor with Suzuki-san trapped beneath them, but no KID.
"Ah, so predictable," KID mocked, holding up the ring which he'd somehow swiped from Suzuki-san, who was currently shouting obscenities at KID. "Honestly, I expecte-" He was cut off by a high velocity soccer ball which he just barely dodged. The ball collided with the wall behind KID, cracks spiderwebbing behind it as bits of plaster came loose. "T-Tantei-kun," the thief said, the stutter barely noticeable.
Masaru looked from his spot in the dogpile to see a young boy with oversized glasses and a stubborn cowlick glaring at KID, his shoes - were they sparking?
"KID," the boy acknowledged.
"Did tantei-han give your older, cuter cousin my message?" KID asked and oh blessed Kannon, Masaru thought, the thief really had no sense of self preservation did he?
Edogawa-kun grinned, a toothy, vicious little thing. "Shinichi-niichan says you can go burn in hell," he chirped cheerily. "And that the next time Ran-neechan calls him because she's upset with him because he ran off on her when it was really you disguised as him, he won't convince her not to break your face."
KID paled and Masaru wondered who this "Ran-neechan" was, that she inspired such fear in an internationally wanted criminal. She sounded interesting.
"I-is that so," KID said.
"Un!" Edogawa-kun nodded with a bright smile. "Also that you should probably stay clear of Osaka or anywhere Kazuha-neechan might be, because of what you did to Heiji-niichan. She's not very happy with you. Oh, and KID-san?"
"Yes?" KID asked, sounding a bit worried and looking a bit nervous.
Edogawa-kun's gaze sharpened and he suddenly sounded much older. "That was a warning shot. This time I won't miss."
Masaru had never seen so many soccer balls in so short a time, and he mentally noted to add "gymnast" to the list of possible professions the office betting pool had on what KID did when he wasn't being a major pain in the ass to law enforcement everywhere. Either that or "contortionist".
Omake:
"Shinichi-niichan also said to stop posing like a model because it makes him look like a smug jackass, which he isn't!" Edogawa-kun yelled at the thief as he kicked another soccer ball at him.