"Start" is a sports anime centered around the competitive world of professional tennis, blending intense matches with personal growth and interpersonal dynamics. The narrative revolves around Haruto Tachibana, a talented yet emotionally reserved high school tennis player who struggles with the weight of expectations following in the footsteps of his older brother, a former tennis prodigy. Haruto’s journey begins when he transfers to Seishin Academy, a school renowned for its elite tennis program, where he aims to refine his skills and confront his inner demons.

The series explores Haruto’s relationships with his teammates, particularly his rivalry with Kaito Shinomiya, a fiercely competitive player with a contrasting aggressive style. Their clashes on the court serve as a catalyst for Haruto’s development, pushing him to confront his fear of failure and redefine his approach to the sport. Alongside Haruto and Kaito, the story introduces a diverse cast of characters, including Yuna Aizawa, a determined and strategic player who becomes Haruto’s closest confidante, and Coach Ryota Fujimura, whose unorthodox methods challenge the team to think beyond conventional tactics.

As the narrative progresses, the focus shifts between intense tournament arcs and quieter moments of character introspection. The matches are depicted with a strong emphasis on strategy, athleticism, and the psychological toll of high-stakes competition. Themes of perseverance, teamwork, and self-discovery are woven throughout, as each character grapples with their motivations and aspirations. The series culminates in a national championship arc, where Haruto and his teammates face their toughest opponents yet, testing not only their skills but also their resolve to grow both as athletes and individuals.