Josuke is the illegitimate son of Jotaro's grandfather, Joseph Joestar. He is a caring, popular, and slightly naive teenager. Inspired by his police officer grandfather's (on his mother's side) sense of justice, he isn't afraid to fight for those in need. He is confronted by Jotaro with the need to eradicate evil Stand users from his hometown, Morioh. He refuses at first, believing that it is not any of his business. However, he quickly changes his mind when his policeman grandfather is killed by a criminal Stand user. With a vow paralleling that of Peter Parker, Josuke decides to deliver justice to evil Stand users in his grandfather's place. Josuke is nice to people and says "Mister" and "Miss" like a normal, polite young man... until someone pisses him off (which isn't very hard to do). The easiest way to do that is to mock his hair, which makes Josuke angry and explosively violent. Josuke grew up with his single mother, never knowing his father Joseph Joestar. Josuke is crafty and has a sneaky streak for money, which is shown multiple times in the story. Nevertheless, he is a dependable and friendly person who is always willing to protect people who need it.
Josuke's Stand power, Crazy Diamond, is a melee Stand with short range (3m). Crazy Diamond has the ability of "restoration". It can repair damage (by returning an object to a previous state) and by extension heal injuries (apart from Josuke's own injuries). It is limited in that it cannot revive the dead. It can, however, restore an item to its raw materials (e.g., a table can be restored to timbers). This ability allows Crazy Diamond to perform a range of interesting feats, including trapping the enemy (by restoring pieces of a broken crate around the target) and tracking (e.g., restoring a torn piece of clothing so that it will seek out what it came from and reattach). Its restoration ability often "malfunctions" when Josuke is angry, causing the object to be improperly put back together. The Stand's name is a reference to Pink Floyd's song, "Shine On You Crazy Diamond".
