Dr. Raichi is the lone survivor of the Tuffles, a race that once lived on Planet Plant before the invasion of the Saiyans. The Saiyans not only massacred the entire Tuffle race, but also stole their technology and conquered the planet; renaming it Planet Vegeta in honor of their king . Raichi managed to escape and found refuge on the Dark Planet and prepared to eradicate the last remaining Saiyans.
On Earth, he sends devices that emit a substance called Destron Gas that can destroy all life. When Mr. Popo finds out that only a few hours remain until the planet's destruction, Goku, Gohan, Vegeta, Trunks, and Piccolo rush to destroy the devices located around the planet. They manage to destroy all but one that is protected by an impenetrable energy barrier. However, Frieza , Cooler , Turles and Lord Slug appear and engage the heroes. It is revealed by King Kai that the villains are ghost warriors and will continually come back to life when killed unless defeated in the same way their lives were originally ended.
The heroes track Dr. Raichi down to the Dark Planet and engage him, discovering that his ghost warriors are generated by a machine called Hatchihyack, a device powered by the hate of the Tuffles. It is also revealed that Dr. Raichi is a ghost warrior himself, generated by Hatchihyack. When Vegeta vaporizes Raichi, preventing him from re-materializing, the hate Dr. Raichi had causes Hatchihyack to exceed its limit. Hatchihyack appears in a powerful android body. Hatchiyack devastates the heroes until the Saiyans, after having transformed into their Super Saiyan forms, combine their powers together into one massive wave of energy, ending the threat.
