Mizuchi is an endangered harlequin rabbit student at Cherryton Academy, immediately recognizable by her distinctive two-tone fur pattern: the right side black, the left side white. She wears the standard Cherryton Academy uniform: a white blouse, bow tie, pleated white skirt adorned with light blue stripes, tan belt, white anklet socks, and black Mary Jane shoes.

Her personality manifests as bigoted, vindictive, and intensely jealous. She exhibits fierce possessiveness over her harlequin rabbit boyfriend, emphasizing that they are one of only two such rabbits at the school. Deep anxiety about her species' potential extinction drives her; she views their relationship as vital for preserving what she considers uniquely noble heritage. This fuels profound resentment towards Haru, a white dwarf rabbit, upon discovering Haru slept with her boyfriend.

Learning of this infidelity, Mizuchi initiated a targeted campaign of harassment against Haru. She spearheaded rumor-spreading about Haru's sexual activities across the campus, resulting in Haru's ostracization. When confronted, Mizuchi defended her actions by revealing her boyfriend approached Haru first due to Mizuchi's own abusive behavior, which had caused him to temporarily end their relationship. In a later encounter, Mizuchi poured water over Haru while declaring Haru's "inferior" species had no right interfering with harlequin rabbits' duty to procreate and avoid extinction.

This bullying persisted until Haru retaliated verbally during the Meteor Festival. Mizuchi and her companions fled when Legoshi approached Haru mid-confrontation. Following this incident, Mizuchi ceased harassing Haru, likely due to fear of Legoshi's intervention. She later reconciled with her boyfriend.

Mizuchi is consistently accompanied by two friends, a flying squirrel student and a black cat student, who actively participate in her harassment of Haru. Documented sources record no further development or appearances beyond these specific events.