Numabuchi Ki'ichirou, who grew up in the Gunma Prefecture, was a serial hold-up murderer who got involved with the Black Organization. He was originally hired to become one of their assassins, but his mental lability soon exempted him from that career. Instead, he was to become a human guinea pig for the new APTX 4869 poison, under the supervision of Miyano Shiho. However, while Shiho had been given his file for close medical study, she didn't get to meet Numabuchi personally; knowing about his impending fate, he escaped the Black Organization. During his flight, he panickedly murdered several people he suspected of being Black Organization pursuers.  While he may be cast as a psychotic serial killer, in the series Numabuchi appears more like a frightened victim. While he may kill without hesitation, he does it mostly out of fear and to regain his freedom. He is shown to have a more sensitive side and a fondness for children when he rescues Mitsuhiko from an ill-fated attempt to present his crushes Ayumi and Haibara with a special surprise.

Kudo Shinichi is a seventeen year-old high school detective whom people call the "Modern Sherlock Holmes." However, one night after a date with his childhood sweetheart, Ran, Shinichi witnessed an illegal trade and, caught off his guard, was knocked unconscious and fed a drug that was supposed to kill him... but he woke up and found himself shrunken to a seven year-old. In order to track down the men who did this to him, Shinichi hid his identity and lived with Ran, whose father happened to be a hopeless detective, and with that came a series of murders and mysteries that he must solve. 
(Source: Anime News Network)
 
Note: 
- Includes Keisatsu Gakkou-hen - Wild Police Story in episodes 1029, 1038, 1042, 1061 
- Episodes 11, 52, 76, 118, 162, 184, 208, 342, 356, 449, 452, 487, 488, 489, 490, 515, 516, 521, 522, 651, 734, 804, 805, 927, 928, 1187 aired with a runtime of ~50 minutes as opposed to the standard 25 minute long episode. 
- Episodes 96, 129, 174, 219, 263, 304, 383, 479 aired with a runtime of ~90 minutes as opposed to the standard 25 minute long episode. 
- Episode 345, 425 aired with a runtime of ~115 minutes as opposed to the standard 25 minute long episode.

[Profile](https://www.aoni.co.jp/search/tatsuta-naoki.html)

Precocious high school student Jimmy Kudo uses his keen powers of observation and astute intuition to solve mysteries that have left law enforcement officials baffled. Hot on the trail of a suspect, Jimmy is accosted from behind and fed a strange chemical which physically transforms him into a grade schooler! Taking on the pseudonym Conan Edogawa, he attempts to track down the people who did this to him. But until he finds a cure for his bizarre condition, Jimmy continues to help the police solve their toughest cases. Can you crack the case before Conan does?
 
(Source: VIZ Media)
 
Note: Won the 46th Shogakukan Manga Award in the shounen category in 2001.

Ki'ichirou Numabuchi