Kei Ogata, a brown-haired male with piercing gray eyes, endured severe childhood abuse at the hands of his biological father, Tomaru Sawagoe, until social services intervened. Relocated to his mother and stepfather, the trauma left lasting psychological and physical scars, sparking an internal conflict between inherited violent tendencies and a yearning for normalcy.

Technologically inclined and introverted, he gravitated toward online anonymity, adopting the alias "A.W." to connect with a user named EVE—later revealed as classmate Midori Nagawa. Their real-world interactions grew strained as Midori’s attraction to his online persona clashed with his guarded secrecy about his fractured identity.

Manipulated into a coercive relationship by Yumi Matou, who preyed on his vulnerabilities, Kei’s suppressed rage surfaced during a summer festival, culminating in the rape of Midori’s friend Miki Sawanaga. Wracked with guilt, he sought redemption by supporting Midori, discarding the A.W. identity to forge an authentic bond.

His moral unraveling deepened: he confessed to assaulting Miki’s younger brother, Taisuke, in a case of mistaken identity, and fathered a child, Korin Sekihata, with Rin Sekihata—his underage half-niece. Reuniting with them years later, he molested Korin, severing their ties and echoing his father’s legacy of cyclical abuse.

Kei’s fractured family tree intertwines with incestuous entanglements, including a romantic link to maternal half-sister Ai Ogata and multiple half-nieces. Records ambiguously note children with both Miki and Rin. His casual wardrobe—orange or light-blue shirts paired with jeans—and middle-school uniform contrast with a haunting resemblance to Tomaru in photographs, a visceral reminder of the cruelty he fears inheriting. Introverted yet analytically sharp, he refers to himself as "boku," a subtle nod to his guarded persona.