Mikako has to move to Hokkaido due to her husband's work. Her best friend Junko is throwing her a farewell party, so she decides to stay at her house. While they are reminiscing about old times, Junko's son Naoto comes home and they spend a good time together, but... That night, Naoto is captivated by Mikako's mature charm and peeks at Mikako as she takes off her clothes in the dressing room before going to the bath. Noticing his gaze, Mikako, with the help of some alcohol, begins to gently seduce him in her everyday beige underwear.