Succubus-san is a Real Adult.While struggling to keep men from being affected by the natural aphrodisiac she produces, Sakie finds herself becoming attracted to Tetsuo when she assumes he wasn't affected. While Tetsuo questions Hikari on the connection between bloodsucking and romance, Kyōko tells Sakie about her crush on Tetsuo and asks for some romance advice, despite Sakie's lack of actual experience. Later, Yuki becomes panicked after she overhears some girls badmouthing her behind her back, claiming that she is being full of herself, and seeks out Tetsuo's help.