Kasumi Mikagekouji holds the position of student council vice-captain at Seiryuu Gakuen, a boys' boarding school, operating directly under President Kusanagi. He actively assists Kusanagi in executing a scheme to compel the central group of five friends to perform in the school's cultural festival play. This involves luring the group to the president's residence under false pretenses and confining them to secure their participation.

A confirmed prior connection exists between Kasumi and Arai, one of the five friends, as they were former roommates. This shared history creates underlying tension during their interactions throughout the play's preparation. Mikimaro, another member of the coerced group, exhibits noticeable jealousy regarding Kasumi's past closeness and interactions with Arai, complicating the group's dynamics during the OVA events.

His actions and relationships unfold primarily within the context of implementing the student council's cultural festival plan, specifically the coerced performance of "Little Women" requiring the main male characters to cross-dress for female roles. His background, motivations, and development beyond this role in the OVA remain focused on these events.