During his summer holiday, Kawasaki Ryuichi (Ryuzaki Ichiro), a handsome engineer in his late twenties, visits his teacher and mentor, Professor Inagaki (Sugai Ichiro), at his seaside home. There he meets the professor's lovely young wife, Sachiko (Hamada Yuriko), and is unsettled by the striking resemblance she bears to his wife, who died three years earlier. Attracted to Sachiko, he does his best to hide his feelings. The couple, however, senses a deep-seated melancholy in him. Attributing it to the loss of his wife, they urge him to marry their niece, Kaoru, but he is not interested. Shortly after, Fumiko , Sachiko's older sister, realizes that Sachiko and Kawasaki have feelings for each other, but she keeps her counsel. One day Kawasaki, Sachiko, and Kaoru go boating when a storm forces them to stay overnight at a hotel. Unable to sleep, Kawasaki takes a walk along the beach where he finds Sachiko, also unable to sleep. He declares his love for her.