The Iwatobi Swim Club has a full roster now.As they begin to practice, they run into a little trouble.After a certain member claims that his swimsuit is to blame, the club makes a trip to buy new swimsuits.

After hearing about what happened in the past, Rei goes to Samezuka Academy to ask Rin what he wants. The night before Iwatobi and Samezuka leave for regionals, Rin calls Rei to explain how he feels about the relay. And then, Samezuka announces its lineup for the relay.

The Iwatobi Festival has begun! Haruka and friends are fired up for the Club-versus-Club Relay Race, hoping to attract new members by putting in an impressive performance. Meanwhile, Rei begins training but is worried by the fact that he can still only swim the butterfly stroke…

The members of the Iwatobi Swim Club ponder over the cause of Nagisa’s odd behavior at the end of practice that day. Though they time their chance well to ask Nagisa what’s happened, Nagisa stubbornly refuses to explain why he’s upset...

While Haruka and the boys redouble their training in the wake of prefecturals, Makoto notices Gou looking troubled and asks her what’s wrong. She tells him that Coach Sasabe has been so busy with his Swim Club lately, he hasn’t been by to approve their new training regimen. Makoto offers to go see him for her, but what he finds at the Swim Club is...

Having faced his feelings honestly at last, Haruka tells Makoto, Nagisa, and Rei what he has decided for himself and his future. The Iwatobi Swim Club is once again fully united as they mount the starting block at nationals, ready to swim for themselves, for their friends, and now, for the future as well.

Haruka's next race is the All-Japan Invitational, which determines who will represent Japan at the global level. To prepare for this important tournament, Haruka is invited to a special training camp.