"Fruits Cup" is a slice-of-life anime series centered around a group of high school students who form an unlikely friendship through their shared passion for a unique sport called "Cup Racing." The sport involves teams competing in relay-style races while balancing delicate, handcrafted cups filled with water. The narrative explores themes of teamwork, perseverance, and personal growth as the characters navigate the challenges of both the sport and their daily lives.

The protagonist, Haruto Aoki, is a reserved and introverted first-year student who initially joins the school's Cup Racing club out of curiosity. His natural talent for precision and balance quickly earns him a spot on the team, but his lack of confidence and fear of failure create tension with his teammates. Among them is Rina Takahashi, the team's spirited and determined captain, who pushes Haruto to embrace his potential while grappling with her own insecurities about leading the team to victory. The group also includes Yuto Nakamura, a laid-back but fiercely loyal upperclassman, and Saki Matsuda, a meticulous and analytical strategist who often clashes with Rina's impulsive decisions.

As the series progresses, the team faces various obstacles, including rival schools with more experienced players, internal conflicts, and the pressure of balancing academics with their rigorous training schedule. Key arcs focus on the team's preparation for regional and national tournaments, where they must overcome personal and collective challenges to succeed. Haruto's growth as a competitor and his evolving relationships with his teammates form the emotional core of the story, while secondary characters, such as the team's supportive coach and their skeptical classmates, add depth to the narrative.

The anime balances lighthearted moments of camaraderie and humor with poignant explorations of the characters' individual struggles. Through their journey in Cup Racing, the team learns the value of trust, resilience, and the importance of pursuing their passions despite setbacks. The series concludes with a climactic tournament arc that tests the limits of their abilities and solidifies their bond as a team.