The new school year begins at Amanogawa High School, and Kengo Utahoshi is detecting strange energies around the school. And things get stranger when yankee-looking Gentaro Kisaragi transfers into the school and decides that he wants to be Kengo's friend.

Kengo reveals to Gentaro that he must turn off the Zodiarts Switch used by the person who activated it in order to truly defeat a Zodiarts. As Gentaro and Yuki search the campus for the owner of the Zodiarts Switch, she begins to tell Gentaro more about Kengo and how he came to have the Fourze Driver and the Astroswitches.

Gentaro and the others decide to bring back those students who were Zodiarts to the school, starting with Toshiya Miura.

To save Miura from using a Zodiarts Switch again Gentaro must go up against one of the Horoscopes, Scorpian, a commander Zodiarts.