S1E10 Irritated Heart Rate!/Plot

The episode begins with Rin Matsuoka's introduction as a new transfer student of Iwatobi Junior High School. Rin tells the class that even though he has a girly name, he is a boy. Makoto Tachibana remembers that Rin had been in a tournament with them.

Flashback to Rin joining the Iwatobi Swimming Club and Rin asking Haruka Nanase to join him in a relay with Haruka refusing, stating that he only 'swims free.' Makoto and Nagisa Hazuki see Rin swim and praise him, while Haruka remains silent. In the locker room, Nagisa approaches Rin and asks if he is forming a relay team, wanting to join. Rin replies that he can join if he place first in the next breaststroke time trial. Excited, Nagisa tells Haruka that he is going to work hard, but Haruka remains indifferent.

Rin asks Makoto why Haruka is 'so obsessed with free.' Makoto replies that he does not think Haruka particularly likes swimming free, but he has never asked, either. Rin wonders is there is any way to get Haruka to participate and Makoto questions Rin as to why is he so obsessed with swimming in a relay. Rin replies that he has his reasons and leaves it at that.

Standing in front of a sakura tree, Rin tells Haruka and Makoto that he is leaving for Australia the day after the tournament in order to attend a swimming school there. The relay will be their last chance to swim together and for Rin to show them 'a sight you've never seen before.'

In the present, Goro Sasabe decides to continue coaching the team for their relay competition. He continuously urges them to practice and to take note of their faults like swimming form, kicks and time. He is soon exasperated and tells them, "you don't know what you're doing." Goro sets up recording equipment at the pool, letting the swimmers check out their form from multiple angles. It proves effective, but Rei Ryugazaki comments that the way Haruka swam before was more beautiful.

On the way home, Nagisa asks Rei what is wrong and Rei replies that he does not understand why Rin suddenly decided to take part in the relay. He complains that their goal is to make it to the nationals as a team, but everyone is talking about Rin instead.

The team, along with Gou Matsuoka and Miho Amakata, is later at Goro's house, eating hot pot even though it is the middle of summer. Nagisa accidentally upsets a stack of old magazines, and Goro realises that the reason he finds Miho so familar is because he has seen her as a swimsuit model in his "special" editions. Miho is flustered until Gou discovers a photo album of the old swimming club and the group begins reminiscing about the past. Rin is in several photos.

On the way home, Rei asks the other three team members what happened to their relationship with Rin, as the old photos showed how close they used to be. Haruka says that he will tell Rei if he is interested and Rei replies that he is, saying that he is tired of 'being the only one on the outside.' Haruka tells Rei about Rin's obsession with swimming relay, adding that Rin only told them the reason just before the final, that being because his father was one of the first members of the Iwatobi Swimming Club. Rin wanted to follow in his father's winning footsteps so that he might be able to share his father's dream of becoming an Olympic swimmer. Haruka talks about the sight that Rin promised to show and says that he felt like he really did see it. Nagisa and Makoto both agree.

Haruka then relates another story. In this one, Haruka runs into Rin during winter break. Rin wants them to swim together again; however, the objective this time is 'to see who is faster.' Rin loses causing him to tell Haruka that he is quitting swimming before running off. Nagisa and Rei now know the reason Haruka quit the swim club in junior high school. Makoto comments that Haruka stopped because he felt guilty. Rei is still confused about why Haruka is upset about Rin losing and why Rin is also entering the relay now. Haruka has no answer, but he states that he is looking forward to racing Rin again. Nagisa tells Rei not to brood on it any more as it is all in the past, and they do not plan on getting Rei involved. However, this angers Rei and he shouts that he is already involved.

The next day, Rei is not at practice and Nagisa makes excuses for him while having some idea about where Rei may be. Rei is actually at Samezuka Academy meeting Rin and telling him that they need to talk.