Makunouchi Ippo has been bullied his entire life. Constantly running errands and being beaten up by his classmates, Ippo has always dreamed of changing himself, but never has the passion to act upon it. One day, in the midst of yet another bullying, Ippo is saved by Takamura Mamoru, who happens to be a boxer. Ippo faints from his injuries and is brought to the Kamogawa boxing gym to recover. As he regains consciousness, he is awed and amazed at his new surroundings in the gym, though lacks confidence to attempt anything. Takamura places a photo of Ippo's classmate on a punching bag and forces him to punch it. It is only then that Ippo feels something stir inside him and eventually asks Takamura to train him in boxing. Thinking that Ippo does not have what it takes, Takamura gives him a task deemed impossible and gives him a one week time limit. With a sudden desire to get stronger, for himself and his hard working mother, Ippo trains relentlessly to accomplish the task within the time limit. Thus Ippo's journey to the top of the boxing world begins. [Written by MAL Rewrite]

Even though it has been a year since the Iwatobi High School Swim Club has been created, new members have yet to join the club. Now that Haruka Nanase and Makoto Tachibana are senior students, along with their younger friends Nagisa Hazuki and Rei Ryuugazaki, they have to find a way to attract new members. If not, the club will be forced to close the following year due to a lack of membership. Meanwhile, with impending graduation, it is also time for the seniors to decide their plans for the future. Unlike their friend Rin Matsuoka, the new captain of Samezuka Academy Swim Club who is determined to fulfill his dream of being a professional swimmer, Haruka and Makoto are unsure about what career path they want to take. Further problems arise when an old friend of Rin's, Sousuke Yamazaki, comes to the city to study at Samezuka Academy; the recently scouted swimmer's arrival causes tension in the relationship among him, Rin, and Haruka. [Written by MAL Rewrite]

Hanamichi Sakuragi, infamous for his temper, massive height, and fire-red hair, enrolls in Shohoku High, hoping to finally get a girlfriend and break his record of being rejected 50 consecutive times in middle school. His notoriety precedes him, however, leading to him being avoided by most students. Soon, after certain events, Hanamichi is left with two unwavering thoughts: "I hate basketball," and "I desperately need a girlfriend." One day, a girl named Haruko Akagi approaches him without any knowledge of his troublemaking ways and asks him if he likes basketball. Hanamichi immediately falls head over heels in love with her, blurting out a fervent affirmative. She then leads him to the gymnasium, where she asks him if he can do a slam dunk. In an attempt to impress Haruko, he makes the leap, but overshoots, instead slamming his head straight into the blackboard. When Haruko informs the basketball team's captain of Hanamichi's near-inhuman physical capabilities, he slowly finds himself drawn into the camaraderie and competition of the sport he had previously held resentment for. [Written by MAL Rewrite]