Incredibly indolent cop Tomokawa spends his time making fun of his mentally challenged friend Sukemasa, riding his bike all over the city and sleeping with married women. When he meets Yoko, the teenager immediately offers him sex in exchange for money, and sparks fly. Soon, they realize they have more of a connection than they thought: Yoko is Sukemasa's sister; Tomokawa slept with their mother; and their grandfather gave him a special tattoo.