One day, Yutaro, who lives alone, meets a married woman, Ai, at a nearby pub. He had a rift with his girlfriend's husband and was at a loss, so he decided to have a drink with her, but... After that, he became friends with her, and before he knew it, he began to have a physical relationship with her. Yutaro gave Ai a duplicate key to her home, and when her husband left for work, Ai started heading to Yutaro's house with her shopping bag in hand. And the couple passed each other