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.
Maki, who has a negative personality and barely gives her opinions, plays the lead violin in the quartet. She has family and only goes to Karuizawa on the weekends for performances. Suzume, who is unemployed, plays the cello, while Yutaka plays the viola in the quartet. The leader of the quartet and the one providing his grandfather's villa as a base for them is Tsukasa. He plays the second violin in the quartet and comes from a musical family. A man of many secrets, he also works at a donut company.