Rin and Aoi, who are fraternal twins, have a close relationship. Aoi is a respected member of her school's kendo club, while Rin's fashion style has caught the attention of many women. Nevertheless, when an ex-opponent from Aoi's kendo team beats her and expresses romantic interest in her, Rin seems to feel jealous for no apparent reason. Aoi is confused by Rin's sudden change in behavior, unaware that he possesses information about her that she is unaware of.