Shinkin Onsen -Beautiful sisters' banquets of obedience -

Nanako, a wife who was supposed to work at a hot spring inn in the back of the mountain to return her husband's debt. Her husband's older sister, Reiko, will go to the inn after hearing her brother's guilt for a nako who takes over his debts and the dangerous rumors of an inn where she works. So Reiko saw this eclectic figure tied up in the carcass so that he could not be frightened. Reiko decides to put her body out of the way. However, the feeling of mahjong that crawls between the crotch gradually infuriates the rationality of the sister-in-law.