Mukuro Rokudo is a 15-year-old Mafia criminal who escaped from an Italian prison, which held some of the most dangerous Mafia criminals, before he was to be executed. Not long after, he, along with his two subordinates, came to Japan, enrolled in Kokuyo Junior High, and started the Kokuyo Gang, which consists of heinous criminals who have recently escaped from prison.Skilled in casting illusions as well as mind control. He attempts to take his revenge on the Mafia by taking over Lancia's body and using him to wreak havoc. When his plan fails due to Tsuna's interference, he is once again imprisoned. However, later on in the series, after possessing the body of Chrome Dokuro, he takes on a more supportive role for the series' main characters, though still prefers not to associate with them.