In modern-day Kyoto, exhausted delivery worker Haru Sato rescues Reira, a mysterious injured woman, from white-cloaked attackers. She is the Devil in human form, and saving her brands Haru’s palm with the Fallen Mark, binding their lives together. Their story blends intense action, horror, dark romance, mystery, occasional humor, cinematic anime visuals, consistent character designs, and cliffhanger endings.