An art student named Jin Mikuriya carves a statue from the wood of the Kannagi tree only to have the statue come to life in the form of a goddess, who has now taken over the statue. He and "Nagi" work together to destroy the impurities that are gathering in the town.
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).