As sadomasochistic yakuza enforcer Kakihara searches for his missing boss he comes across Ichi, a repressed and psychotic killer who may be able to inflict levels of pain that Kakihara has only dreamed of.

A masochistic mobster meets his match in the dark streets of Tokyo. His nemesis, Ichi, is a psychopathic killer with an unrelenting thirst for bloodshed. A horrifying secret burns in his mind, and his hands deal death without mercy. At last, the shrouds of mystery are parted to reveal the origin of the monster. The city will know its greatest fear at the unveiling of Ichi the Killer.

Bad things happen when innocent blood is shed. In the early 1700s, Lord Sodom Ichibei is happily celebrating his wedding day when his wife-to-be suddenly dies. In his search for an explanation, he kills any and every suspect he comes across. When Lord Ichibei tortures and kills two innocent girls, their death brings about a curse on the Sodom family. Three hundred years later, one of Sodom's descendents, Ichiro, is also set to be married. But one of the innocent victims has been reincarnated as Ichiro's sister and she kills everyone at the wedding. This transforms Ichiro into the evil and vengeful "Sodom The Killer", a cursed man hell-bent on slaughter and the world's destruction...