Medical student Makoto Tachibana took advantage of his summer break to visit Sado Island, the hometown of his best friend Tago. Tago was the son of the owner of a ryokan in Ryotsu Port on Sado, and his younger sister, the aspiring singer Chieko, had also come to the island. The day Makoto arrived on the island was the opening ceremony for the Ryōtsu River, and the entire town was buzzing with the Okesa dance. That night, Chieko introduced Makoto to Fumiyo, whom she had noticed on the ferry and had been curious about. Although Makoto and Fumiyo were attracted to each other, her grandfather and older brother vehemently opposed their relationship.