Mayu, a married woman, befriends her husband's friend, Kayama, gradually opening up to his warm personality and diverse interests. However, one day she gives in to his advances and engages in a physical relationship, unable to refuse. Shaken by his lonely expression, she is overwhelmed with guilt over her betrayal. Having gone without intimacy with her husband for a long time, deep down she begins secretly wishing to be taken by Kayama. Even when she reluctantly visits his house at her husband's request, her feelings remain unresolved, continuing to torment her.