A yakuza boss has disappeared with a huge sum of money, and hitman Kakihara (Tadanobu Asano) is willing to do literally anything to find his boss. An extreme sadomasochist, Kakihara enjoys not only tormenting the people he tortures, but also his own suffering. That’s why he is eager to get on the trail of psychopathic killer Ichi (Nao Omori), who is involved in the mobster’s disappearance. Kakihara hopes that the fight with Ichi will be the high point of his experience with pain.