Overhearing an argument between her mother Tomoko and family friend Sawada, Taneko, a sheltered 21-year-old student, discovers that her father Shinzo has been formerly married, and that her mother enticed Shinzo from her own second cousin, Asako. During a flight to Tokyo Shinzo chances to meet Asako, now married, whom he has not seen for 20 years. At the airport, while waiting for her father, Taneko meets Shintaro, a fellow student to whom she has been attracted for some time. He is at the airport waiting for Asako, who is his mother. During the summer vacation the students fall in love, but Taneko is shocked when Shintaro discloses his earlier involvement with a promiscuous woman employed at his father's hotel. At an art exhibition Shinzo and Asako again meet by accident and discover that they both have hoped for such a meeting. Asako, curious about Shinzo's present family, unexpectedly arrives at his home one evening. [Sources do not disclose the film's ending.]
Released in Japan as Kawano hotoride.