Goro Arashiyama is the dedicated lifeguard patrolling the beach home to the Lemon Beach House restaurant, fiercely protective of both the sea and its visitors. He sports a tanned complexion, short brown hair, brown eyes, and a muscular build, usually clad in his red lifeguard swim trunks and a red-and-yellow striped swim cap, often working barefoot. Professionally serious, Goro possesses a distinct soft spot: he finds it impossible to refuse any request from Chizuru Aizawa, the older sister of his childhood friend Eiko Aizawa. This devotion pushes him to extremes, like continuing to attack Chizuru during self-defense training despite sustaining severe injuries that landed him in the hospital. He nurses a long-standing, unreciprocated crush on Chizuru, driving him to jog with her despite exhaustion and secretly keep photos of her on his phone. His relationships are varied: he shares a deep childhood bond with Eiko Aizawa, maintains a competitive rivalry with Squid Girl whom he sees as a menace to beach safety, and shows kindness to their younger brother Takeru, offering swimming lessons partly to win Chizuru's favor. Goro's mother, a retired champion sumo wrestler who occasionally appears, has developed an interest in scientific research involving other characters and habitually overfeeds people, influenced by her own substantial eating patterns. A longtime acquaintance of the Aizawa family across all media, Goro's storylines consistently highlight his comically persistent pursuit of Chizuru and unwavering commitment to his lifeguard duties, frequently colliding with Squid Girl's chaotic antics.