The film is set in Enoshima, Shonan, and revolves around four teenagers on the island: Yuki Sanada, Haru, Natsuki Usami, and Akira Angelokaru Yamada. High school student Yuki Sanada (voiced by Ryouta Oosaka) is a transfer student. He is not good at socializing and often shows a scary expression because of nervousness. Haru (voiced by Miyu Irino) claims to be an alien from space who came to Earth to fish. He not only lives in Yuki's house without permission, but also invites Yuki to go fishing. Yuki, who has no friends, participates in fishing because of Haru's appearance. Later, they met Natsuki Usami (voiced by Koki Uchiyama), a "fishing prince" born and raised in Enoshima with super fishing skills, and Akira Angelokaru Yamada (voiced by Tomokazu Sugita), a mysterious transfer student from India. Haru has been forcing Yuki to learn fishing on the grounds that "only we can save the earth", and Yuki, who has no choice, asks Natsuki for fishing skills. On the other hand, the mysterious Indian Akira has been secretly observing them because he accepted the organization's mission. What kind of youthful sparks will the encounter of these four people collide with?