Kiyotaka Matsuno is an eighteen-year-old diver from Japan who appears as a rival to the Mizuki Diving Club, representing a team called Mare Tokushima. His surname, Matsuno, combines characters meaning pine tree and field or wilderness, while his given name, Kiyotaka, uses characters for clear or pure and filial piety or obedience. Kiyotaka is characterized by a self-conscious nature and a tendency toward negative thinking. No information is available regarding his specific background, motivations, precise role in the story beyond being a rival, key relationships with other characters, character development throughout the series, or notable diving abilities.