Waka Ninomiya, a married woman whose husband is away for work, suffers from unbearable boredom and loneliness. One day, while doing a deep cleaning, she develops back pain due to lack of exercise and loses the motivation to go outside. Around this time, she becomes interested in a popular new delivery service. The man who arrives for the delivery is friendly, and they quickly strike up a conversation, growing closer with each encounter. As their intimacy deepens, Waka's sexual frustration intensifies. Whispering, "You... I'm sorry," she blames herself, yet sincerely convinces her mind she's done nothing wrong. This fleeting affair begins to ripple through her heart in unexpected ways.