A housewife, Saijo Kinuka lives with her husband Makoto and her high school daughter Honoka and her middle school son, Yuto. Due to the death of Makoto's father, they decide to move to a large European style house in Kamakura, with the second wife of Makoto's father, Saijo Chizuko. There, they host a home welcoming party, at which Kinuka invites her guests such as Suganuma Kyoko and company peers of Makoto. To every sense of the word, it is a perfect party in a perfect new environment. Like Chizuko will show-off her belly dance skills in front of everybody. This is when something shocking happens. While Kinuka is preparing for the party, suddenly her ex-boyfriend Seno Itsuki appears out of the blue. Due to loan payments which he has to deal with, he had decided to live in the attic of her new house!
