Green Lovers (1975)

Two innocent high school girls, Aki Shindo, nicknamed Ako, and Mineko Mayama, nicknamed Neko, run away from home and, along with Kaori Yashiro, whom they meet while hitchhiking, arrive at a certain beach. There, at a yacht harbor, they find Daisuke Sakuma, whom they met in town. Daisuke had come there to head to the Galapagos Islands at the request of his seniors, Yamamuro and Akira Kanno.