After divorcing her husband, Natsumi and her only daughter Kyoko move into an old house. However, a few days after moving in, the bathtub breaks down. It's summer, and Natsumi and Kyoko feel uncomfortable with their sticky bodies. They buy a bathtub for women only that they received from the newspaper delivery man. They head to "Senjoyu" (female bath), but... However, for some reason, Natsumi is taken to "Shirayuri" instead of Kyoko. There, Natsumi meets Natsuko. At that time, Natsumi had no idea that "Shirayuri" was a "lesbian bath"...