The husband became obsessed with shogi, and his wife, Maki, felt both exasperated and happy watching him play with her nephew, Masato. One day, the husband had to leave suddenly for work, leaving Maki alone with Masato... Masato had secretly desired Maki since long ago, and unable to resist her unguarded allure, he took his chance and pushed her down. Maki tried to resist, but because she had been sexless with her husband, she unconsciously felt a perverse desire for his robust body and ended up accepting him. From that day on, the two's hidden sexual desires spiraled out of control, disrupting their daily lives...
