Mikako is forced to move to Hokkaido due to her husband's job transfer. Before parting ways, her closest friend, Junko, invites her over for a farewell gathering, and Mikako decides to spend the night at Junko's house. As the two reminisce about old times, Junko's son, Naoto, returns home and joins them. Naoto becomes captivated by Mikako's mature charm, and that night, he secretly watches her undress in the changing room before taking a bath. Under the influence of alcohol, Mikako, wearing her everyday beige lingerie, begins gently seducing him. The atmosphere intensifies, and their relationship takes an unexpected turn.