My wife is about to give birth! My sister-in-law and I came to help with the housework.

Her husband, Hiroki, lives modestly in a small apartment with his pregnant wife, Mari. When Mari reaches the end of her term, Rio, her older sister, decides to stay with her as a housekeeper for the time being. From the moment they met, Hiroki fell in love with Rio's charm, and the bottom of his nose kept growing. Meanwhile, Mari suddenly feels like she's going into labor and goes to the hospital! The baby was born safely, and Torio Hiroki celebrates at home. The two get drunk and lose their sense of reason at home without Mari...