Hakuchû joshi kôsei o okasu (1984)

Tatsuo, a high school student, lives each day with mixed feelings because his father has remarried a young woman. He confides in Onodera, the owner of a snack bar. One day, Tatsuo spots two high school students, Kumi and Noriko, on the beach. They are runaway girls, and Kumi's boyfriend was swept away by a wave while surfing in that very sea and is now missing. Tatsuo is drawn to Kumi, but Onodera, the bar owner, also has his eye on her…