Fushimi Ren lives by "lacking" death. He wishes to complete what he is lacking, in other words, he wants to die. On his way back home, he meets a girl, Sherazade, who loves "lack." This self-proclaimed witch said that she will grant Ren's wish, but... Gathering to the mystery club "Lacking Club," (Ketsuraku-bu) the activities of the group of youth who are "lacking" begin.