Second year high school student Koguma doesn't lead a very interesting life. She has no parents, and no friends nor hobbies to keep her daily life busy. One day, she acquires a second-hand Honda Super Cub motorcycle and rides it to school. As time goes by, not only does Koguma have a new adventurous life, but she also forges precious friendships thanks to her precious little motorcycle.

Yura Yamato has just arrived at the high school division of Stella Women's Academy, when Sonora Kashima invites her to join a club called "C³". Sonora is the third-year student who became the new head of this club for military survival games. The other members include two second-year students (part-Japanese Karila Hatsuse and G36K-wielding Honoka Mutsu) and two other new students (Rento Kirishima whose family runs a Japanese sweets shop and the really short Yachiyo Hinata).

Hikaru is at first sight a student like others but actually it is a super hero defending the Earth of the demons. He has a powerful super bike and a combat suit. Inspired by the classic Space Sheriff (Uchuu Keiji) trilogy of the Metal Heroes Tokusatsu franchise, namely Space Sheriff's Gavan and Sharivan.

Mika Katagiri wants her band to perform at the upcoming local festival. However, complications arise. Their keyboardist, Jun, refuses to play, and their stage has been cancelled. Refusing to give up, Mika and her band strive to find a way to play at the festival, using any means necessary.