Kentarō Tachibana coaches the Kitakomachi High School women's badminton club. A college student standing 181 cm tall, he has brown eyes and dyed blonde hair, a symbolic gesture for the "gold" of a gold medal. His own background as a former competitive badminton player deeply informs his coaching. A Men's Inter High tournament champion in high school with Olympic aspirations, a knee injury prematurely ended his athletic career. This experience fuels his vigilance over players' physical health, leading him to stop Nagisa Aragaki's exhausting match against Connie Christensen to prevent a potential career-ending knee injury.

Tachibana exhibits persistence and sharp observation, notably recruiting Ayano Hanesaki after witnessing her agility and motor skills despite her initial reluctance. His coaching philosophy focuses on nurturing talent for Olympic success, driven by his own unrealized dream. While he effectively supports Nagisa through technical limitations like overreliance on her jumping smash and mental struggles including performance anxiety, his approach to Ayano's deeper psychological trauma—rooted in her mother's abandonment—remains limited. He acknowledges her backstory but does not substantially address the behavioral shifts it causes during competitions.

His personality merges enthusiasm with pragmatism. He often wears distinctive cool shades, sometimes giving him the air of a recruiter rather than a traditional coach. His attire typically includes a white shirt, black pants, and a sky-blue jacket, later switching to a black-and-red shirt. Tachibana balances sternness during training with underlying care for the athletes' long-term welfare, though his effectiveness varies between managing physical injuries and emotional complexities.