Ryohei and Misa are a married couple who both work. Since Ryohei spends most days working from home, he cannot stop thinking about a beautiful woman he sometimes meets in the elevator. Her name is Ichika, a married neighbor who attends the same yoga class as Misa. One day Ichika loses her key, and Misa innocently invites her inside to wait for her husband—giving Ryohei the chance he has been craving.