A man broken by his parents' divorce finally feels something real, then discovers it's for his sister. The show doesn't flinch from what that means. It builds toward an ending that refuses to punish desire itself, only the choices made in its name, and that restraint is more devastating than any moralistic shutdown could be.

Saeki Koushirou, 28, plans weddings for a living, yet his own love life is a mess. His parents divorced, and he lives with his father, having not seen his mother or sister in years. After his girlfriend leaves him, he drifts through his days without really living. Then he notices a high school girl, Kohinata Nanoka, on his morning train and feels an instant pull toward her. He soon learns she is his sister, and that she is coming to live with him and their father. What follows is a psychological romance and slice-of-life drama about feelings he cannot easily put aside.