Masaki drifts into surfing by accident, then drifts away from the people who taught him, and the show doesn't pretend that's a clean moment. The animation moves like water, not like ambition. This is a movie about growing up feeling like losing, told by someone who cares more about how your chest feels than how your turns look.

In Ooarai, a coastal city in Ibaraki prefecture, 14-year-old Masaki Hinaoka has never cared about surfing, even though it is his best friend Nalu Tanaka's favorite hobby. That changes when he spots Shou Akitsuki, a blond transfer student, riding the waves at sunrise. Shou happily helps Masaki get started, and although Masaki cannot swim, he picks up the sport far faster than anyone expected. His progress earns him a place in a local competition, where he meets other talented surfers who push him to get better. Surfing brings Masaki new friends, but on his way toward adulthood it also sees him drift apart from them, in a sports slice of life story.