An unwary custodian is transformed into Janemba, a big, yellow demon who wreaks havoc throughout the afterlife, as a result of a janitorial incident. Since his heroic death in the battle against Cell, Gokuu Son has been competing in zombie martial arts championships. Janemba's turmoil eventually pulls Gokuu and fellow warrior Pikkon to him, requiring the two to devise a strategy to kill the gigantic monster. After a fight with him, Gokuu observes Janemba undergo another transformation: the demon loses weight and changes color, transforming into a sword-wielding foe more strong than anybody Gokuu has met thus far. Gokuu must stop the frightening Janemba from destroying the whole fabric of the universe with the help of his equally deceased opponent Vegeta.