A series of events leads single, 25-year-old Mikuri Moriyama and 36-year-old Hiramasa Tsuzaki to marry as a cover.

Maki Maki, Sebuki Suzume, Beppu Tsukasa and Iemori Yutaka happen to meet and form a quartet. They even begin to live together in Karuizawa during the winter, but there is a big hidden secret.