Nobuo, a book editor, is married to Aya, a former model turned nursing assistant. Aya has a sex addiction, and on sunny days, she sleeps with other men, causing anguish for Nobuo and guilt for herself.

Nobuo is a book editor with a sincere personality. He is married to Aya. She used to work as a reader model, but, after their marriage, she now works as a nursing assistant at a nursing home. Nobuo is aware that his wife has a sex addiction and she will sleep with other men on a sunny day. Nobuo agonizes over his wife and Aya carries heavy guilt over her actions.