Souta is a second grade student. One day at night, Nemu, who calls herself a succubus, appears at his window. This is the beginning of a comedy between a clumsy succubus and an elementary school student.

One day, Tarou Yamada, who runs a detective business, slips on a banana peel and reincarnates into Tsukushi Shikisaki, the younger brother of three beautiful big-breasted sisters who will all die on the same...