"Teppei" is a sports anime centered around the life of Teppei Takamiya, a young boy with a passion for tennis. The narrative begins with Teppei's introduction to the sport during his elementary school years, where he discovers his natural talent and begins to develop his skills. His journey is marked by a series of challenges, both personal and competitive, as he strives to become a top-tier tennis player.

The story progresses through Teppei's middle and high school years, highlighting his growth as an athlete and an individual. Key characters include his family, who provide both support and occasional conflict, and his peers, who range from rivals to close friends. Notable among these is Ryoma Echizen, a prodigious tennis player who becomes a significant rival and source of inspiration for Teppei. The interactions between Teppei and Ryoma are pivotal, driving much of the competitive tension and personal development within the series.

As Teppei advances through various tournaments, the anime delves into the technical aspects of tennis, showcasing different playing styles, strategies, and the psychological battles that occur on the court. The matches are detailed and intense, often serving as the climax of individual story arcs. The series also explores themes of perseverance, teamwork, and the importance of balancing ambition with personal well-being.

Throughout the narrative, Teppei's character is tested by injuries, setbacks, and the pressures of competition. These challenges force him to confront his limitations and adapt his approach to the game. The support system around him, including his coach and teammates, plays a crucial role in his ability to overcome these obstacles.

The anime concludes with Teppei reflecting on his journey, having achieved significant milestones in his tennis career while also gaining a deeper understanding of himself and his relationships. The ending leaves room for interpretation regarding his future, emphasizing the ongoing nature of personal and athletic growth.