Free! is a Japanese anime television series produced by Kyoto Animation and Animation Do. The series is loosely based on the light novel, High Speed! (Japanese: ハイ☆スピード!, Hepburn: Hai Supīdo!), written by Kōji Ōji, which received an honorable mention in the second Kyoto Animation Award contest in 2011 and was published in July 2013. The first season titled, Free! - Iwatobi Swim Club for international distribution, aired in Japan in 2013; and the second season titled, Free! - Eternal Summer, aired in 2014. A third season of the anime series titled, Free! - Dive to the Future, aired in 2018. Hiroko Utsumi directed the first two seasons, while season three was directed by Eisaku Kawanami.

Prior to season three, several films depict events preceding, including and following the events of seasons one and two. The first feature film, High Speed! Free! Starting Days, was released in December 2015 and depicts events from volume two of the series' prequel light novel, High Speed! A film trilogy was released in 2017 with the first two films being compilations of seasons one and two of the anime series titled, Free! Timeless Medley - the Bond and Free! Timeless Medley - the Promise. The third film in the trilogy titled, Free! Take Your Marks, features four new vignettes. A compilation film encompassing the third season titled, Free! Road to the World - the Dream, debuted in July 2019.[2]

The next installment of the franchise was slated for release alongside the Tokyo 2020 Summer Olympics, but both were postponed until 2021. A final film duology titled, Free! The Final Stroke, debuted in Japanese theaters in two parts: Part 1 in September 2021 and Part 2 in April 2022.

Free is set in the town of Iwatobi, Japan, which is based on Iwami, Tottori. The story is centered on high school student Haruka Nanase, a gifted swimmer. After encountering his childhood rival, Rin Matsuoka from Samezuka Academy, he and his friends revitalize Iwatobi High School's swim team. In addition to his childhood friends, Makoto Tachibana and Nagisa Hazuki, Rei Ryugazaki is recruited onto the team. While the team trains for tournaments, Haruka and Rin's rivalry continues to sour from Rin facing setbacks in improvement, though his desire to swim competitively escalates. However, during the prefectural tournament, Iwatobi's swim team reminds Rin of their friendship through a medley relay. Despite being disqualified, the boys' relationships with one another improve.

In Free! Eternal Summer, Haruka, now in his final year in high school, has not decided on what to do after graduating. Meanwhile, Rin's childhood friend, Sosuke Yamazaki, transfers to Samezuka Academy. Rin hopes to swim competitively with Sosuke but, unbeknownst to him, Sosuke has injured his shoulder from overuse. During the regionals, Haruka becomes overwhelmed from the pressure of performing in front of scouts and becomes lost on what to do for the future. He further learns that his best friend, Makoto Tachibana, is leaving Iwatobi to attend university in Tokyo. Haruka withdraws from all social contact. However, with help from his friends and a trip to Sydney, Australia, where he visits the International Aquatic Centre, he decides to continue his swimming career and compete on the college level.

In Free! Dive to the Future, Haruka attends Hidaka University and reconnects with his friends from junior high school, with the exception of Ikuya Kirishima, who is still bitter about their former team breaking up without explanation. In order to make amends with Ikuya, Haruka begins training in other strokes besides freestyle and eventually competes in an Individual Medley alongside him. Although they mend their friendship, Haruka is faced with the reality that he will be competing against swimmers at his level and higher. Despite this, he commits to continuing his swimming career and to competing on the global level.

In Free! The Final Stroke (the first volume), Haruka, Rin, Ikuya and others make the Japan National Swim Team and compete at the global level in qualifying events and at the Fukuoka Tournament. In Free! The Final Stroke (the second volume), Haruka, Rin, Ikuya and Sosuke compete in a medley race, win gold medals, and become national champions.