The samurai is plunged into a dystopian world ruled by Aku, adopting the name “Jack”. After getting in a fight at a nightclub, he is hired by a group of canine miners to protect them from Aku’s forces.
Jack infiltrates a rave party after witnessing the participants stage a riot in a nearby town. It turns out that the DJ is one of Aku’s servants, and has been using his music to hypnotize the local children into becoming his master’s slaves.
Jack survives a series of traps and encounters a Viking king transformed into a giant rock figure by Aku, who insists that Jack slay him in battle so that he can reach Valhalla.
Seeking to end their struggle, Aku proposes a one-on-one duel between him and Jack, with neither combatant using their magic abilities. Jack agrees, but Aku’s honesty is unclear.
When Jack hears rumors of a time portal being found in the underwater city of Oceanus, Jack sets out to the city and is welcomed by its Triceraquins, but is unprepared for a terrible surprise.
When a gang of robot bikers destroy his sandals, Jack seeks revenge, but realizes that he can’t do so without footwear, something he has difficulty choosing.
Centuries ago, the demon Aku is accidentally released by Jack’s father, who receives a magic sword from the gods. Eventually, he uses the same sword to imprison Aku beneath the earth.
