Mitsugu stands among the three central figures in the narrative alongside Moemi and Reina. She joins her peers in a collaborative project documenting their early sexual explorations via self-recorded videos.

Exhibiting markedly greater curiosity about sexual matters than the more reserved Moemi and shy Reina, Mitsugu's proactive approach fuels the group's collective activities. Their documentary shifts from initial recordings of sexual discovery toward increasingly explicit kinky content as the trio delves deeper into bodily and sexual exploration.

Mitsugu openly discusses sex with her peers and engages in mutual experimentation. This uninhibited behavior directly influences the selection of erotic themes within their film project. Her actions and attitudes significantly steer the video's thematic progression from straightforward documentation to more extreme adult material.

The narrative offers no details on Mitsugu's background, origins, or existence beyond the depicted events. Her character arc concludes without resolution or revealed fate. Similarly, she appears solely within this single OVA, with no portrayals in other official media including seasons, films, spin-offs, or alternative adaptations.