Tenmasou is a long-established inn atop a mountain overlooking the sea, in a town called Mitsuse that exists between heaven and earth. The inn is run by Nozomi Tenma, the proprietress. Her younger sister Kanae works as a dolphin trainer. Their mother Keiko is the inn's elder proprietress, who is still resentful of her ex-husband that deserted his wife and family.

In Kyoto, Mayuko (Haruka Ayase) stands at a crossroad in her life. She's thinking about marriage with her boyfriend Kyoichi (Hiroyuki Hirayama). By an accidental opportunity, Mayuko stays at Honnouji Hotel. There, she meets historical figure Nobunaga Oda (Shinichi Tsutsumi) who is attempting to unify Japan.