入江家に1ヶ月間同居することになった従妹の理加は、頭が良い上に美人。しかも、直樹とファーストキスをしたと聞いて、オロオロと焦るばかりの琴子。妻のプライドをかけて料理をするが、直樹からは｢まずい｣の一言。そんな琴子に、理加は｢直樹を返して｣と言うが......。 Naoki's cousin Rika comes to the Irie household to stay for a month, and she is smart an beautiful. Not to mention Kotoko finds out she's Naoki's first kiss, making Kotoko worry. With her pride of being his wife on the line, she tries to cook him a meal but gets a "It tastes bad" comment from Naoki. Kotoko is then told by Rika to "give Naoki back" but...