Junta is a husband living with his wife who is in the final month of pregnancy. As this is his wife's first childbirth, her older sister Akari comes over to help with the housework. In contrast to his childish and selfish wife, Junta is smitten with Akari, who is kind and full of adult charm. Meanwhile, a healthy baby is born safely, and Junta and Akari celebrate at home. Akari gets drunk and mistakes Junta for her husband...