The franchise's story is set in a world over a decade after futsal has skyrocketed in global popularity. Protagonist Haru Yamato watches the championship of the U-18 world cup and is inspired by a Japanese player named Tokinari Tenōji. He joins the Koyo Academy High School's futsal team with the goal of becoming a player like Tenōji. There, he finds friends, and together they face their rivals.

It, a mysterious immortal being, is sent to the Earth with no emotions nor identity. However, It is able to take the shape of those around that have a strong impetus. At first, It is a sphere. Then, It imitates the form of a rock. As the temperature drops and snow falls atop the moss, It inherits the moss. When an injured, lone wolf comes limping by and lays down to die, It takes on the form of the animal. Finally, It gains consciousness and begins to traverse the empty tundra until It meets a boy. The boy lives alone in a ghost town, which the adults abandoned long ago in search of the paradise said to exist far beyond the endless sea of white tundra. However, their efforts were for naught, and now the boy is in a critical state. Acquiring the form of the boy, It sets off on a never-ending journey, in search of new experiences, places, and people. [Written by MAL Rewrite]

After last season's revelations, the Souma family moves forward, but the emotional chains that bind them are not easily broken. Unable to admit why she wants the cure, Tooru wrestles with the truth, aware that time is running out for someone close. And a secret still lurks that could break another's heart. But hope is not lost—a clue to the curse is found. Could their imprisonment's end be near? (Source: Funimation)

Haruka Nanase's new stage is Sydney, the place of his dreams that he once visited. One day while taking a short break before his departure, Haru has a chance confrontation with a fellow athlete from the All-Japan Invitational. Carrying all the feelings from those he's swam with in his heart, Haru takes his first step forward into a new world. Waiting for him there is the unmistakable champion, Albert Volandel. In the lead up to the Sydney tournament, all the competitors attempt to boost their morale. What is each competitor feeling, and what do they swim for, as they attempt to compete at the top of the world? Their passionate struggle against the water begins from here――！