On a winter night, a man whose wife has left him is invited by a friendly neighboring couple to share dinner together. Amid the harsh cold season, they enjoy warm drinks and sushi under the kotatsu. The conversation grows lively, and before long, the man and his friend's wife begin touching each other under the kotatsu. The husband, drunk and unaware, falls asleep, allowing the man to proceed with lewd acts on the married woman. Rarely having had chances to meet before, she gradually gives in to the situation, ultimately having sex with him right under her husband's nose.