S2E13 The Eternal Summer of Beginnings!/Plot

Makoto Tachibana meets Haruka Nanase and Rin Matsuoka at the airport, being his usual self. They travel to the venue for the nationals where Rin departs to meet up with his team and Haruka thanks him. Nagisa Hazuki and Rei Ryugazaki welcome Haruka back to Japan. Haruka announces that he has something to tell the team. He explains that he never cared about winning or his timing because he believed that if he did, swimming would lose its meaning. And, he wasn't able to respond to their concern because he did not believe that he could find his dream just by looking. However, after travelling to Australia, he realizes how big the world really is and found his dream there, which is wanting to enter the world of global competitive swimming. So, for the sake of that dream, he will start caring about timings. The others are glad that Haruka has been able to sort things out and found his dream, adding that they will support him.

In a private moment with Makoto, Haruka apologies for their confrontation at the Obon festival. However, Makoto says that he is the one who should be sorry because he could not tell Haruka about his future plans. He felt that he is not suited for competitive swimming, but after helping Goro Sasabe out at ITSC RETURNS, Makoto realizes that he wants to be a coach, showing children how fun it is to swim. He is going to a university in Tokyo to achieve this.

After dinner, the Iwatobi High School Swim Club reminisces about their history in the swim club, including its rocky start, recruiting Rei, as well as Nagisa's issues with studying. Rei lets it slip that he had help from Rin and learns that the team already knew. They talk about their first relay and how hard they have trained for the following day. Nagisa declares that they will proceed even further and be more amazing next year, after which Rei reminds him that the third-years are retiring. As his words sink in, Rei starts crying, surprising Makoto and Haruka. Nagisa starts crying, too, saying that he wants the four of them to keep swimming together. As they continue bawling, Makoto comforts them, saying that they are swimming together tomorrow. Haruka agrees, stating that even if they are apart, they are still connected.

The next day, their relay starts. Iwatobi wins their heat, and everyone is overjoyed at the completion of the relay.

At Samezuka Academy, there is a traditional send-off for the graduating third-years. Debriefing his team, Rin appoints Aiichiro Nitori as the next captain. Afterwards, Sosuke Yamazaki stares at the pool alone. Rin tells Sosuke not to crush his potential before he even tries, adding that he will be waiting for him to come back to the swimming world. Sosuke comments that it is exactly what Rin would say, referring to the time when he encouraged Aiichiro.

The team heads to the ISCR, where they bury a time capsule containing the sights they saw during the nationals. They then head to Samezuka Academy, where a pool filled with cherry blossom awaits them.

In a flashforward Makoto is seen studying hard while Haruka is training under a coach in Tokyo. There are plenty of members joining swimming club, delighting Nagisa and Rei. Nagisa is managing his time between his studies and swimming. Hayato Shigino is continuing his swimming lessons at ISCR, where it is revealed that the team placed 6th during the national tournament. Rin and Haruka are once again in adjoining lanes, facing off against each other.