Kouichi serves as a sailor aboard the fishing vessel *Koganei Maru*, spending weeks at sea that strain his family life. His maritime obligations keep him from home, sparking occasional tension with his wife, Lisa, who voices discontent over his extended absences. To bridge the distance, he communicates via Morse code with the ship’s lamp and illuminates decorative lights on the vessel—gestures Lisa meets with indifference. The family resides in a coastal town, where Lisa and their five-year-old son, Sōsuke, await his return. Amid a supernatural tempest born of ecological discord, Kouichi’s ship is caught in a towering wave illusion formed by clustered boats. Here, he meets Granmamare, the sea goddess, whose divine presence stabilizes the storm. She restores the ship’s power, compelling Kouichi and his crew to pledge gratitude for her mercy. Kouichi’s squared jawline and short dark brown hair, partially hidden under a New York Yankees cap, complement his practical khaki attire. A reddish life vest and binoculars accompany him during seafaring tasks. His bond with Sōsuke is marked by heartfelt exchanges: the boy prays fervently for his father’s safety, while Kouichi signals loving messages through the lamp, their connection enduring despite separation. After the storm subsides and nature’s equilibrium returns, stranded ships reunite with the port, allowing Kouichi to embrace his family once more. His acceptance of Ponyo’s metamorphosis into a human underscores his faith in Sōsuke’s choices and mirrors the narrative’s emphasis on coexistence between humans and the natural world.