Sayuri Fujimura is 44 years old and lives with her husband and son. In the family life she has built over many years, there has been no sexual relationship with her husband. One day, she accidentally saw her son masturbating, and the image became deeply imprinted in her mind, eventually leading her to try it herself. However, her son caught her in the act, and though filled with guilt, he began to sense the emotional distance between his parents. Since then, he has started pursuing her in places like the kitchen and bathroom, and days have passed where she feels the absence of her husband more and more. This kind of secret is something she never wants anyone to discover.