Hiroyuki Ando, a shy and insecure young college student, was hospitalized with a broken leg. During treatment, he encountered nurse Yoshimi Terada and developed intense romantic feelings, captivated by her gentle and caring demeanor. This infatuation stemmed partly from a minor attraction years earlier when both attended the same evening school, though they never formally interacted.

Driven by unresolved emotions, he secretly followed her outside the hospital. This stalking revealed her concealed double life: by night, she worked as dominatrix Yumi, expressing deep-seated contempt for men through sadistic practices. Confronting this reality, he paid for a session. Yumi mocked his naivety and innocence, deliberately humiliating him. Paradoxically, the experience triggered a profound personal revelation, uncovering his latent masochistic tendencies.

His inability to reconcile Yoshimi’s dual identities—compassionate nurse and cruel dominatrix—fueled emotional turmoil. Actions driven by confused desire and rejection of her true nature culminated in inadvertently harming those he cared about, particularly Yumi. This failure to accept reality caused irreversible personal transformation, cementing his role as a tragic figure whose initial vulnerability devolved into self-destructive behavior.