Miho Shirakawa, a 28-year-old nurse at Gouriki's medical clinic, maintains an outwardly calm and mature demeanor, occasionally revealing a mischievous streak. Her hobby is learning capoeira.

Burdened by significant debt, Shirakawa resorts to illicit activities to manage her obligations. She diverts drugs from the clinic to sell on the black market and participates in coerced honey trap schemes targeting wealthy men, orchestrated by criminal elements. These actions create underlying tension within her character.

Shirakawa shares a significant past as the ex-girlfriend of the gangster Dobu, connecting her to the criminal underworld. Despite her compromised circumstances, she demonstrates concern for Hiroshi Odokawa. She intervenes decisively to prevent harm when his life is threatened by Fuyuki Yamamoto.

A pivotal revelation clarifies Shirakawa is human. Her perceived animal appearance (initially depicted as an alpaca) stems from Odokawa's visual agnosia, a psychological condition distorting his perception of people as anthropomorphic animals following a childhood trauma. This condition affects his view of everyone in his surroundings.

Shirakawa navigates the consequences of her debt, her involvement with criminal figures, and her interactions with Odokawa. The resolution of her storyline involves Odokawa negotiating the cancellation of her debt with Dobu as part of a broader agreement. Following the climax, she continues her nursing position and is implied to share a closer, potentially romantic relationship with Odokawa.