Leo, who was imprisoned and tortured to death by the gangster Damian in his previous life, is reborn to save his seriously ill sister and is forced to become Damian's "substitute plaything" again. Under the desperate circumstances of public humiliation, a failed escape, and his sister's "tragic death," Leo resolutely drinks poison, casting the most vicious curse with his life. Three months later, Leo survives but loses his memory. The once-violent Damian hides his fangs, claiming they are a loving couple, and weaves a new cage called "love" with extreme tenderness. Until the blood-stained diary is blown open by the wind, the shocking blood-written word "RUN" awakens the soul-deep fear engraved in his memory.