To avenge her father's death, Yumi became an assassin and tracked down her archenemy, Kirisaki, launching her mission to fulfill her goal. However, her plan collapses due to an unexpected turn of events. Upon arriving at the enemy's hideout, Yumi faces a terrifying situation—her fiancé, Yoshihide, is held captive. Cornered by the threat that any resistance will result in Yoshihide's death, Yumi, overwhelmed by fear, is brutally raped in front of her helpless fiancé. This single traumatic moment drastically alters the course of Yumi's life.