Transfer student Takisawa Noboru quickly learns that all disputes at his new school are settled in the boxing ring. Now he finds himself in a series of showdowns with the local top dog, Ibuki Saburo, for the love and respect of the beautiful Yukari.

Following the conclusion of the National Middle School Tennis Tournament, 12-year-old tennis prodigy Ryouma Echizen sets out to the United States in order to further improve his tennis skills. While finding his own way to shine in the sport, Ryouma investigates a perplexing development: the circumstances behind his father's retirement from professional tennis. Known as "Samurai Nanjiro," Ryouma's father Nanjiro is a legendary tennis player whose career abruptly ended after the US Open finals several years prior. Though Ryouma has studied the final match extensively, there are still many gaps in his understanding—gaps that he would only be able to fill by watching the match in person. As luck would have it, a supernatural phenomenon transports the young prodigy—and his unsuspecting classmate, Sakuno Ryuzaki—back in time to that very event. Although the events that occur before the game seem normal at first glance, the appearance of the mafia soon complicates the mystery behind the retirement. Despite the bad odds, Ryouma must do everything he can to unravel the circumstances and prevent his father's career from ending.

"First muscle training animation ever," a 16-year-old girl named Hinako leads exercises in push-ups, sit-ups, and squats. Hinako was once a human, but she was turned into an anime character when she was a second-year middle-school student.

Subaru Hasegawa has the ambition to become one of the best basketball superstars of all time. However, this comes to an apparent halt when his school's basketball team ceases activities for a year. Shocked by the news, he decides not to involve himself in basketball anymore. One day, his aunt Mihoshi Takamura invites him to coach the Keishin Academy girls’ basketball team on how to play the sport, and he reluctantly agrees. He meets sixth-graders Tomoka Minato, Maho Misawa, Airi Kashii, Hinata Hakamada and Saki Nagatsuki, and begins training them in the sport with one goal: to defeat all strong opponents along the way. Ro-Kyu-Bu! follows the effort of five elementary girls and their coach as they their cute style of playing basketball.