Gentaro and the Kamen Rider Club must figure out how to deal with Haru as the Musca Zodiarts and Mr. Ohsugi's discovery of the Rabbit Hatch, along with the latter's confiscation of the 38th Astroswitch.

After the 39th and 40th Astroswitches are developed, Amanogawa and Subaruboshi High Schools hold a test transfer of some of AGHS's students to SBHS, which causes problems when the Aries Zodiarts makes itself known to the AGHS students...

After Gentaro's death at Ryusei's hands, Kengo does not know how to resurrect him as the Aries Zodiarts takes the other Kamen Rider Club members captive. Elsewhere, having betrayed Tachibana, Ryusei is able to talk to the revived Jiro.