Mikage Onohara is a 19-year-old female standing 158 cm tall with pale skin. She possesses medium-sized breasts measuring 85 cm, her nipples visible. Her waist-length pink hair is styled with curtain bangs parted down the middle, frequently arranged in twin tails adorned with ribbons or flowers. Her eyes are a striking red. Typical attire includes dresses, thigh-high stockings, a choker collar, and bell accessories.

Her background stems from her parents selling her into slavery to the vampire Claude, resolving their crippling financial debts. This transaction severed her family ties and bound her as Claude's property, his payment covering their outstanding obligations.

As Claude's property, Mikage undergoes specialized training to serve as his sustenance source, deriving nourishment through anal stimulation rather than blood. This regimen involves repeated anal penetration using fingers, beads, vibrating devices, and eggs, progressively intensifying over time. The process inflicts physical strain and discomfort, including sessions with wine bottles inserted into her rectum.

Her existence centers on enduring this training while striving to repay her perceived debt to Claude, aiming ultimately for freedom. The documented narrative concludes without resolution, leaving Mikage's status as an enslaved trainee unchanged.