SK8 the Infinity

Langa, a transfer student from Canada, meets Reki, a skateboarding enthusiast involved in a risky underground race called "S" held in an abandoned mine. When Langa seeks part-time work, he accompanies Reki to the race as an assistant. There, Reki is confronted by Shadow, the rival responsible for his past injury, and Langa is unexpectedly drawn into the dangerous event despite having no skating experience.

Langa, having defeated Shadow in a competition, reveals his snowboarding expertise and becomes a rising figure in the "S" community as a mysterious newcomer. Seeking to recapture the thrill of the competition, he begins learning roller skating from Reki, gradually discovering the unique challenges and joys of the sport.

Langa, rapidly improving in his skills, is challenged to a competition by Miya, a seventh grader and potential member of the Japanese national team. Despite Reki's concerns, Langa agrees to the match, though Miya's advanced skating ability proves difficult for the team. As Reki supports Langa during training, he observes something significant just before the competition begins.

Following Langa's victory over Miya, Adam, the founder of the "S" skateboarding team, makes a surprise appearance. Reki, insulted by Adam's comments about Miya, challenges him to a skate battle, which Adam accepts on the condition that he also races Langa. After learning a difficult trick from Miya and training with his friends, Reki faces off against Adam in an intense showdown.

Reki is seriously injured in his fight against Adam, prompting Langa to step in and challenge him. Despite Reki's pleas for Langa to back out, Langa remains resolute and determined. Together, they seek advice from Cherry Blossom and Joe in hopes of finding a strategy to overcome Adam's powerful Love Hug.

Reki, still recovering from his fight with Adam, follows Miya's suggestion to visit Miyakojima for hot spring treatment. There, the group encounters Cherry Blossom and Joe, and a race ensues to reach a secret spring, soon shadowed by an enigmatic presence hinting at a hidden secret on the island.

Reki regains his ability to skate after recovering from injuries, but he becomes increasingly aware of the skill gap between himself and Langa, leading to feelings of insecurity. As their relationship strains, Adam makes an unexpected announcement that shifts the dynamics between them.

Langa competes in a tournament to determine the top skater in "S," but his rival Reki chooses not to participate due to a deep-seated sense of inferiority. Langa is troubled by Reki's absence as the qualifiers progress, while the arrival of an enigmatic new skater stirs controversy among the competitors.

Langa advances past the qualifiers and faces off against Joe, a formidable competitor known for his exceptional power skating, which puts Langa under intense pressure and causes him emotional turmoil. Meanwhile, Adam competes against Cherry Blossom, whose strong conviction toward him prompts a shift in Adam's demeanor and hints at a shared history between the two.

Cherry Blossom faces a decisive and painful defeat at the hands of Adam, prompting Kikuchi to enter the main tournament driven by personal resolve to stop him. At the same time, Reki begins to understand his own emotions but remains uncertain about the path forward.

Reki reflects on his passion for skating and strengthens his connection with Langa, but this draws the attention of Adam, who then sets his sights on Reki. As a result, Reki faces a rematch with Adam, an opponent who once defeated him decisively, though he now approaches the challenge without fear. Reki and Langa share a heartfelt moment before Reki prepares to confront Adam in the finals.

Adam wins the battle against Reki, but Reki remains unfazed and continues to enjoy the competition. Observing this, Kikuchi concludes that only Langa can offer Adam a true challenge and withdraws from the race. As Reki and Langa prepare to face Adam, they make a significant promise before the final showdown begins.