Ichi the Killer: Episode Zero is a movie that delves into the origins of the infamous character from the original Ichi the Killer film. It explores the deeply disturbed psyche of Ichi and showcases the extreme violence and gore that he becomes known for. Set in Japan, this anime-style adult animation is a brutal ride into the dark depths of mental illness and sadomasochism.

Ichi the Killer follows the story of Ichi, a sadomasochistic yakuza enforcer with an abusive childhood. When his boss is killed, Ichi goes on a mission to find his killer, crossing paths with Kakihara, a masochistic psychotic killer. The two engage in a violent and bloody battle, revealing dark secrets along the way.

1-Ichi tells the story of a young high school student named Ichi who seeks revenge on a group of bullies after they brutally attack his friend. With a troubled past and a deep hatred for violence, Ichi embarks on a mission of mercilessness, using his skills in sadism and violence to inflict pain on those who have wronged him.