On the day of the Tennomifune Academy entrance ceremony, in the class 1-7 classroom, Hanakoizumi Anne (Hanako), Hibarigaoka Ruri (Hibar), and Kumegawa Botan (Botan) are told by their homeroom teacher Kodaira-sensei that they are unfortunate and unhappy students. The goal of the students of class 1-7, who are burdened by a variety of forms of misfortune, is to become happy. The three girls have trouble accepting their circumstances, but they're immediately given an unexpected assignment...!