Midori possesses masochistic tendencies, finding sexual arousal in violence and physical pain. She actively seeks violent encounters for erotic gratification, deliberately acting as a catalyst to trigger Ichi's emergence as a killer. During their hotel encounters, she manipulates Ichi into inflicting brutal physical abuse upon her, framing his violence as an expression of connection and intimacy within her sexual desire.

Her background is largely undefined, lacking concrete details about origins, family, occupation beyond martial arts skills, or motivations beyond her masochistic drives. She appears solely as an instrument accelerating Ichi's transformation into a conditioned killer. Following her role in facilitating his violent awakening, she receives no further character development or narrative resolution.

Her characterization is confined solely to the origin story OVA, "Ichi the Killer: Episode Zero," with no presence, development, or continuation in other official media such as sequels, prequels, spin-offs, or alternative adaptations.