Masaki Hinaoka, a 15-year-old Ōarai native, discovers surfing through transfer student Shō Akitsuki, whose mentorship ignites his fervor for the sport despite his comically inept swimming—a trait likened to a corgi’s paddling, amplified by his spiky, ear-like hairstyle and loyal corgi companion, Isokichi. His vibrant surfboard, adorned with a sunset motif, mirrors his tenacious spirit.

With fair skin, tousled light-brown hair, dark brown eyes, and bold brows, Masaki dons a black-and-grey wetsuit accented with orange, symbolizing his raw enthusiasm and novice status. His expressive reactions to teasing or encouragement reveal a blend of earnestness and insecurity, yet his resilience pushes him through near-drownings and wipeouts, fueled by loyalty to friends and a drive to improve.

Admiration for Shō anchors their bond, tinged with unspoken depth, until Shō’s implied drowning shatters Masaki’s world, plunging him into guilt and sorrow. Through grief, he clings to surfing, guided by mentors like Hayamichi Inada and buoyed by Nalu Tanaka, whose teasing "Corgi" nickname masks steadfast support. As friendships shift with age, Masaki evolves from mimicking others to crafting his own style, bridging past struggles with newfound resolve. His journey—marked by loss, camaraderie, and saltwater perseverance—cements his role as the emotional core of a community weathering life’s tides together.