Rintaro Senkawa, an unremarkable man in his mid-twenties, drinks too much one night, falls, and dies, waking up in Hell. Waiting for him is Koyori, a small, barely dressed devil assigned to torture him until he repents for the life he led. Her tools run to the spiked iron club, and Rintaro proves far more interested in Koyori than in taking his sentence seriously. Between punishments, the mismatched pair settle into an oddly domestic afterlife.