Youkaiou Kyun Gakuen

A yokai who unites with the “Golden Essence” will give birth to the Yokai King. Chimogami Ousu, who has just become a high school boy, finds himself enrolled in a class consisting of nothing but 13 beautiful yokai girls! Possessing the Golden Essence necessary to give birth to the Yokai King, Ousu is the yokai girls’ top candidate for boyfriend. The curtain rises on a school life filled with one love-stealing battle after another, all orchestrated by these beautiful yokai girls.

(Source: Young Animal, translated)