In the heart of the Japanese Alps, in Kamikochi, Nagano Prefecture, botany professor Kazuhiko Onuma spends time with Tsuruko, his lover. One night, Kazuhiko's wife Kazuyo comes to see them and confronts the professor about his extramarital affair, and Tsuruko, an inevitable witness to the confrontation, leaves the professor the following morning. Over the next decade, whenever he visits the mountain cabin every autumn equinox, the memory of Tsuruko will forever haunt Kazuhiko...