Hina Saotome, once an ordinary office worker and treasurer for a multinational corporation, faced false embezzlement charges leading to a one-year sentence in Black Wing Prison. Orphaned after her parents' accident, she initially relied on her boyfriend Yakumo Kiyonori for emotional support. Identified as prisoner "3077," she wore the standard white inmate uniform. Physically, she stands approximately 160 cm tall with wavy brown hair, brown eyes, and a curvy figure often noted as attractive. Systematic abuse defined her incarceration, primarily from Chief Guard Aki Myojin. He subjected her to invasive "body checks" and sexualized punishments disguised as discipline. Maintaining her innocence proved futile; her sentence extended an additional year following a failed escape attempt planned with Yakumo, thwarted by Myojin. During confinement, she applied medical knowledge—learned from her nurse mother—to treat injuries, contrasting her struggles with manual tasks like kitchen duty and laundry. Hina's personality blended inherent kindness and determination with growing vulnerability. Fellow inmate Higa Yamato protected her from prisoner rape during a punitive lockdown, forging a bond. Their relationship evolved into mutual affection, though Hina initially resisted due to loyalty to Yakumo. This connection provoked Myojin's intense jealousy, leading him to punish them through public humiliation and sexual violence. Hina grappled with internal conflict as physiological responses to abuse made her question her self-worth and identity. Prolonged manipulation deteriorated her psychological state. After a staged prison transfer, Myojin raped her in a transport vehicle while Higa listened helplessly. A subsequent crash during an escape orchestrated by Higa's allies led them to a yakuza safehouse. There, the captive Myojin triggered a conditioned obedience response using her prison number ("3077"), compelling her to free him despite understanding the danger. This act revealed the depth of her brainwashing, cementing her status as his exclusive prisoner beyond Black Wing's walls. Her relationships shaped her trajectory: Myojin used her for vengeance tied to his mother's coma and President Yuzuru Akatsuki's death (Hina's framer), while Higa represented fragile hope for protection and connection. By the conclusion of documented events, Hina remained psychologically entangled with Myojin, her agency subsumed by his control despite physical escape from the prison system.