Demon Pond by Masahiro Shinoda (1979)

A man from Tokyo, Gakuen Yamazawa, passes through a mountain village while returning from a summer field trip. The source of the only stream in the small village is Demon's Pond. The locals believe that a dragon resides there and that the water is poison. There he meets Yuri Hagiwara, a woman who asks him to tell her a story. His second story upsets her and she refuses to let him stay, but her husband Akira awakens and welcomes Yamazawa, his old friend from Tokyo.
Akira had left to gather stories from the countryside but believes that he has ended up becoming one of the stories because he is now responsible for ringing the local bell for the village at matins, vespers, and the mid-watch of the night instead of wandering and enjoying his freedom. He made the promise to a dying seventy-nine-year-old man named Yatabei who had performed the same function for fifty years based on the conviction that the water from Demon Pond will flood the populated areas of Kotohiki Valley beneath Echizen's Three Province Peak if it the bell is not rung at the correct times. Akira now calls himself Yatabei, has married Yuri, and refuses to return to Tokyo despite Yamazawa's urging. Yamazawa decides to climb to Demon Pond and Akira accompanies him, leaving Yuri responsible for the bell.