Mysterious Detectives

The renowned phantom thief, Kaitou Joker, and his apprentice, Hachi Fuuma, traveled to Tropical Land for a heist, where they encounter the high school detective, Shinichi Kudo.
However, during the heist, Joker and Shinichi are captured by members of a criminal organization, who attempt to kill them with an experimental drug. Instead of dying, though, both Joker and Shinichi's bodies end up shrinking into the size of children.
Now, Joker and Shinichi must cooperate to take down the organization and find an antidote that'll return their bodies back to normal - not knowing of the various mysteries, enemies, and rivals that awaited them along the way.