"Rinkai!" is an anime series centered around the world of competitive cycling, specifically focusing on the Keirin races, a popular form of track cycling in Japan. The narrative revolves around a group of young women who aspire to become professional Keirin racers, navigating the challenges of training, competition, and personal growth. The story begins with the protagonist, a determined and passionate cyclist, joining a prestigious Keirin training school. Alongside her peers, she undergoes rigorous physical and mental preparation, learning the intricacies of the sport, including strategy, endurance, and teamwork.

The series delves into the dynamics between the main characters, each with distinct personalities and motivations. The protagonist is driven by a desire to prove herself in a male-dominated sport, while her teammates face their own struggles, such as overcoming self-doubt, balancing personal relationships, and dealing with the pressures of high-stakes competition. The narrative explores their camaraderie and rivalries, highlighting how their interactions shape their growth as athletes and individuals.

As the story progresses, the characters participate in various races, each serving as a milestone in their development. The races are depicted with a focus on strategy and intensity, showcasing the physical and mental demands of Keirin. The series also touches on the broader cultural and societal aspects of the sport, including its history, the role of sponsors, and the expectations placed on athletes. Through its portrayal of the challenges and triumphs of competitive cycling, "Rinkai!" offers an engaging and informative look into the world of Keirin, emphasizing themes of perseverance, teamwork, and the pursuit of excellence.