Seven years have passed since the death of Cell and Goku. The Earth has remained fairly peaceful during this period. Gohan is attending high school in Satan City (renamed after the "champion" who resides there) as there are no schools in his rural area. Gohan notices a bank being robbed one day while going to school, and intervenes to stop the crime. To disguise himself, he goes Super Saiya-jin. Once at school, he meets Videl, daughter of Mr. Satan, who finds him suspicious. Gohan does his best to lie low, but doesn't do a very good job of it.

Worried about people finding out who he is, Gohan asks Buruma to make him a disguise. The "Great Saiyaman" foils a few more crimes with the help of Videl, who's still a bit suspicious of Gohan. But it seems Gohan is more concerned with how he makes an entrance than catching criminals.

One day while landing at his school, Gohan is shocked to see a girl waiting up there for him. When she talks to him, she tells Gohan that she knows his "secret," and that he must go on a date with her or she'll tell everyone. While on the date, Gohan sees a skyscraper burning downtown, and Videl coming to the rescue. Knowing Mr. Satan's daughter, Gohan goes into the building to help. After the day is saved, Angela (Gohan's date) believes that Videl is his girlfriend. With that, she tells Gohan's big secret: He wears teddybear underwear.

Gohan stops a few more crimes, always just ahead of Videl's detective work (Such as the kidnapping of the mayor of Satan City by the Red Rock gang). However, when Gohan tries to return a baby Dinosaur kidnapped from the mountains, Videl stands in his way. After a short scuffle, everything is righted, but not before Gohan accidently reveals his identity. In exchange for not telling anyone, Videl forces Gohan to come to the next Budoukai.