Free! follows Haruka, a talented swimmer with a deep connection to water. He reunites with his elementary school friends, Rin, Makoto, and Nagisa, after years apart.
However, Rin's changed and is now focused on surpassing Haruka, creating tension among them.
Haruka, Nagisa, and Makoto establish a swim club at their high school, Iwatobi, needing a fourth member to compete.
They recruit Rei, and the group works together, strengthening their bonds as they prepare for a tournament.
The season explores their relationships and the central conflict between Haruka and Rin, showcasing their passion for swimming and competition.