The ninja village of Reibe has been in decline since the end of the Sengoku era. Once renowned for its sexual arts, the village is now home to dozens of kunoichi — and only one male ninja, Kagemaru. Kagemaru attempts to flee the village, but is quickly caught. The village chief offers him one path to freedom: endure ten nights of "night-service battles" against the village's kunoichi without being broken by them. Train Kagemaru during the day, learn new techniques, explore the surrounding area, earn money and prepare for each night's battle.

Win, and Kagemaru may finally earn his freedom. Lose too badly, and he may find himself serving the village permanently.