Mr. Satan is challenged to a fight by an old rival, and he is taken to an island where the fight is to be held. Accompanying him are Android 18, who is making sure he doesn't skip town before paying the money he owes her for letting him win the World Martial Arts Tournament, and Trunks and Goten, who are stowaways. When they get there they find that the rival doesn't want to fight himself, but rather has created a force of genetically engineered bio-warriors to fight Satan. Unfortunately for everyone involved, one of these bio-warriors was made from the DNA of Broly, and when he is released, all bets are off.