Rin Matsuoka/Relationships

Samezuka Academy=

Having heard of Rin's success and hard work from Seijuro Mikoshiba, Aiichiro Nitori looks up to Rin as a mentor and role model. He regularly accompanies Rin while he trains   and enthusiastically helps him in any way he can. Initially, Aiichiro and Rin were not on the same team, however, once Rin joined the Samezuka Academy swim team, the two became teammates. Rin finds Aiichiro to be a bit overwhelming and overbearing, but admires his stamina and dedication to swimming. At first, Rin refers to Aiichiro only by his last name but, following his work with the Iwatobi Swim Team, he off and on simply calls him "Ai." In return, Aiichiro happily addresses Rin as "Rin-senpai."

Sosuke Yamazaki joins Sano SC in the third grade of elementary school when Rin is already a member and can swim butterfly. Rin forces Sosuke to join and learn swimming butterfly, too, and Sosuke is left saying, "Ugh, just shut up." Since Rin is faster and isn't saying anything wrong or untrue, Sosuke lets him attempt to teach him butterfly, even though it greatly irritates him. Their relationship remains in that state for over a year until Sosuke becomes a good match for Rin. Because Rin is the one who taught Sosuke how to swim, things like the timing of their breaths or the way they move their arms are exactly alike and, as Sosuke once stated, he couldn't seem to shake it, it was just ingrained then. During the time he was at Sano SC, Sosuke and Rin's relationship is friendly.

When Rin says that he wants to go Australia and when he says that he wants to swim at Iwatobi SC, just saying ‘I understand’ while feeling half shocked, he doesn't try to hold him back or press with too many questions. Sosuke keeps being someone who understands Rin well until the end.

In High☆Speed！, Rin states that it’s better if he's not on the same team as Sosuke because they "understand each other too well". He says that Sosuke’s even more theoretical than he is and that they often quarreled. They agree that the faster way is always correct, but their competitive spirit isn't half-baked anymore. He says that he doesn't hate him. Rather, he still thinks of him as the person who understands him the most, but sometimes it becomes difficult to be around him. When he ends up understanding Sosuke's feelings, he ends up not being able to say the things that he wants to. He can no longer seriously go up against Sosuke because he is that one friend who gets him way more than his other friends, and that makes Rin feel uncomfortable. He says that is not a friend, but an alter-ego (you don’t like or hate your alter-ego).

Even though Sosuke and Rin don't see each other in a long time, they're still great friends. Sosuke likes teasing Rin, as seen when Rin asks him if he's going to stop swimming and has a special type of a handshake with him. Sosuke is very concerned about Rin and his future and greatly dislikes anybody who stands in Rin's way to success, including Haruka Nanase who, according to Sosuke, did "something Sosuke would never do."

Initially, Seijuro and Rin did not know each other at the beginning of the series despite attending the same academy because Rin did not join the swim team at first. However, once Rin joined the Samezuka Academy swim team, the two became teammates and, so to speak, friends.

Despite being Rin's senior and captain, Rin isn't all that close to Seijuro, often addressing him simply as "Mikoshiba" when he's not around. However, the moment Seijuro appears, Rin addresses him politely as "Captain". Rin does not see Seijuro to be very responsible and finds that he is a bit too whimsical. However, he still respects him as his captain and fellow teammate. Rin does not tolerate Seijuro's attempts to go on a date with his sister and often stands in his way. When Seijuro names Rin the next captain, it shows that Seijuro shows respect for Rin. He trusts him to run the team well. They display shows of being good acquaintances

Iwatobi High School=

Gou Matsuoka is often worried about her brother. One of her main reasons in becoming Iwatobi's swim manager is that the guys will help bring her brother back to normal. Rin in response appears sightly protective of her as well especially in response to Seijuro's attempts to go out with her. However he isn't over protective due to his lack of communication with her, even when he returns to Japan.

In the drama CD, Rin was curious about Gou going out every Sunday, and thought that she went on dates with Seijuro. He even called Makoto Tachibana and asked him what are they doing on Sunday. After Rin and Nitori stalked Gou, they were surprised that Gou was actually being helped by Chigusa Hanamura to buy Rin a Christmas present, and that she wrote on the card "Thank you for everything, onii-chan". Hanamura said that she's jealous of Gou to have such a good-looking brother, but Gou admitted that he can be a pain sometimes and that he's never honest with his feelings.

Their relationship in Seasons 1 and 2 depicts an early friendship that becomes a one-sided rivalry, Rin being preoccupied with being better than Haruka in swimming. whose extraordinary talent, yet seemingly casual attitude towards competitive swimming, frustrates Rin to no end. Rin's best stroke is the butterfly, but his desire to race Haruka, who only swims the crawl stroke, leads him to focus on that stroke and whatever distance Haruka swims in competition.

In elementary school, Rin is on the same swimming team as Haruka, Makoto and Nagisa Hazuki. After winning a tournament, Rin goes to Australia to study swimming. When he returns home on winter break, Haruka and he race with Haruka winning. Rin is disappointed and refuses to take Haruka's extended hand. When Haruka learns that Rin quits competitive swimming, he thinks it's his fault and quits, as well. Later, when Rin returns for high school in Japan, they again race and when Rin wins, he's still not satisfied as Haruka is not swimming at top form. He urges Haruka to swim competitively again and Haruka takes this to heart. When Rin officially defeats Haruka at a prefectural tournament, Rin proclaims he will never swim with Haruka again, disappointing Haruka. Makoto tells Rin that Haruka thought something else mattered more, but Rin fails to understand that Haruka seeks his friendship above all.

In S1E12 Distant Free!, the Iwatobi team overhears Rin saying that he's quitting competitive swimming again, which Haruka again takes personally. Rei Ryugazaki assures them that Rin's actions aren't due to Haruka in either the present nor the past, but to Rin's own insecurities and that his true desire is to swim with his friends again. Haruka sets off and finds Rin at the tree they planted at the Iwatobi Elementary schoolyard. When Rin sees him, he becomes upset, putting himself down. Haruka tries to tell him that he was one who taught him that friendship was what made him swim, but before he can do so, Rin tackles him. Falling to the ground, they wrestle, but upon seeing the phrase "For the Team" imprinted in the cement, Rin begins to cry, wondering aloud why they can't swim together as they did before. Haruka replies it's not too late and when the rest of the Iwatobi team arrives, they agree on a plan.

In a last minute change of swimmers, Rin replaces Rei and the team wins the relay. Rin is the first to hug Haruka saying he won't forget that day. Haruka echoes the thought as the rest of the team joins their group hug. In the end credits, it's seen that Rin and Haruka's friendship is restored with Rin stating that he plans to follow his father's dream (which is unspecified) while Haruka's plans remain uncertain.

In S2E01 Storm of Dive and Dash!, the Iwatobi team meets up with Rin at Samezuka Academy in an event to send off the 3rd-year members. Rin and Haruka race, with Rin telling Haruka he'll "light a fire in him." They tie for first place, setting a new record. Later, Haruka confronts Rin, telling him to come to the Iwatobi pool where the team captures him and leads him to a pool filled with cherry blossoms. When Rin says it's too cold to be swimming, they try to push him in but are stopped when it begins to rain. Later still, Rin asks Haruka and Makoto about their future plans, with both of them uncertain.

In S2E09 Forming of Disruption!, Haruka stops swimming mid-event, feeling the pressure of college scouts watching him while he himself feels the water caging him, instead of freeing him. Rin confronts him afterwards in anger, telling him to take his talent seriously, to have a dream. Haruka retaliates with equal hostility, saying that he doesn't have a dream or a future, that he's not like Rin. When Haruka walks away, Rin's disappointment is evident.

In S2E12 A Swim-Off in a Foreign Land!, Haruka is anxious and depressed from the pressure to have a dream and from hearing that Makoto will be leaving to attend college in Tokyo. Rin shows up unexpectedly at his house, telling him they're going on a trip. Perplexed but willing to go along in his sad state of mind, Haruka follows him to Australia. There, Rin takes the opportunity to apologize for his behavior at the tournament, saying he ignored Haruka's feelings by forcing his own on him. He also says that he's always admired him and feels relieved that he's finally told him. Rin then takes Haruka to the ocean, hoping he'll feel better by the water. They chat about the fight Haruka had with Makoto, with Rin saying that he and his best friend, Sosuke, often fight. He then shares his experiences in Australia, including his difficulties, which helps Haruka see Rin's growth because of his life outside of Japan.

Rin then takes Haruka to meet his home stay parents, Russell and Lori, who comment on how Rin has always looked up to Haruka and talked about him all the time. Rin refuses to translate for a questioning Haruka, saying it's unimportant. That evening, upon arriving at their hotel, they're surprised to learn their room has only one bed. Haruka wonders if it's normal for Australia, but Rin tells him it's not. They get into a petty quarrel, with Rin finally going to the front desk to clear up the mistake. With the hotel fully booked, they're stuck, so they must share. Haruka tells him it won't matter when they're asleep; however, they end up staying awake, talking about their memories of one another. Rin admits he didn't think anyone could beat him, but when he saw Haruka swim, he realized "there's someone more amazing than me. I want to be able to swim like him." He adds that it's hard for him when Haruka isn't there to inspire him. Haruka says he, too, remembers. They also reminiscence about setting a new tournament record together with Rin stating that when he felt Haruka coming up next to him, he knew for sure he was going to "enter the same world as him." They then fall asleep.

The next day, Rin takes Haruka to the Aquatic Centre, where the best swimmers in the world race against each other. They spot the National Team practicing there and Rin says this is where they should practice. Haruka asks if they're allowed and Rin challenges him saying no one without guts would swim beside the National Team. In response, they head to the pool with Haruka stepping onto a starting block. When a National Team member steps up beside him and says, "Let's go!" Haruka imagines what it would be like to stand there with thousands of people cheering in the stadium. He feels the rush of competition and, in his mind, reconnects swimming with flying free, as his arms are seen to become wings. He wants to to keep swimming in that place forever. Back in the present, Rin is next to him, saying they should go, too. Haruka agrees, smiling.

Before returning home, Rin and Haru (symbolized as two doves in the sky) discuss their futures once more. Rin tells Haru that his Australian coach wants him to return. Rin says he will formally ask to join the team and, this time, not lose but take revenge. Haruka says, "Rin, I've found it too," meaning a dream for his future. They stand side by side with the doves above flying off in the same direction.

Upon arriving home, Haruka thanks Rin for his efforts which Rin answers with a squinted, whole-hearted smile. After nationals, the Iwatobi team joins him in a petal-filled pool at Samezuka, where they all swim together. They are later seen going in their respected directions, with Haruka attending and swim training at a Tokyo university and Rin swim training in Australia. The season ends with a picture of Haruka and Rin facing off in a professional circuit.

When Rin first transfers to Iwatobi Elementary School, Makoto is much more open and kind to Rin than Haruka, who--at first--doesn't want to get involved.

In the High☆Speed！ novel, their relationship is detailed a little further, impacted by an incident by the riverbank, where they save Haruka as their friend Aki rushes to call the ambulance and several contacts. After Haruka is hospitalized, Rin and Makoto walk to the bus stop together, with Rin expressing anxiety. Makoto tries to reassure Rin that Haruka will be fine, smiling--but Rin reveals the person he was scared for was Makoto, who, when they saved Haruka, couldn't stop shaking.

Afterwards, Makoto feels a responsibility placed on him by Rin to ask if Haruka would join the relay with them, and once they do, Rin and his relationship continues to build. From the riverbank incident on, Rin keeps a subtle eye on Makoto, at one point jumping in to calm him when he seems to have trouble with the water, and Makoto comes to find it easy to joke around with and tease him, and freely laughs at others' joking about him. As seen in the beginning of Free! , late in High☆Speed！ Makoto realizes and becomes apprehensive over whether Rin will stay in Iwatobi or go some place else, and determinedly calls Rin by his first name--the second to last to do so--cementing their bond during these years.

When Rin returns to Japan from Australia, he ignores Makoto and Nagisa in favor of challenging Haru, brushing them off with "You're still hanging out with these guys Haru?" Makoto, still remembering their childhood bond, converses with Coach Goro Sasabe worrying over why Rin had become so distant, and calls him afterward asking that he join Samezuka's swim club so that they could see each other some day soon. When Nagisa confirms Rin joined, he's very happy. And sometime later, despite Rin's supposed dismissal of him, when Gou mentions to Rin that Makoto came with them to the ocean, a flash of anxiety for him passes by his face again, showing that he too remembers their bond after all. He wakes up in the middle of a storm worried about Makoto, and in the morning runs to the beach to check if he and the team are safe.

It's only after Rin wins against Haru at regionals that the Iwatobi boys meet him again, bumping into him while looking for Haru. When Rin assumes Haru is upset due to losing against him, Makoto chides him, reminding him that swimming meant something more to Haru, and he's pretty sure that Rin was the one who taught him what it was. In the finale, after Haru and Rin heal their rift, Rin rekindles his friendship with the boys, able to laugh with them again.

Rin initially does not think highly of Rei when he first sees him swimming a relay with the boys. He instantly becomes jealous and does not think he swims well. Rei then confronts Rin at Samezuka in episode 11, asking him why he joined the relay, what happened to him in Australia, and what he really wants from Haruka. Rin gets defensive and asks why he has to answer these questions and also questioning Rei why he wants to swim in a relay. Rei tells him the same answer Rin gave when he was younger, saying he desired to swim with his friends and be the best team around. Rei then leaves. Further on in the episode Rin contacts Rei and tells him the answers to the rest of his questions. Others=

Unlike Makoto and Nagisa, Rin calls Aki Yazaki the more formal "Yazaki-san." In High Speed!, Rin thinks Aki is someone who can influence Haruka's way of thinking, and although he later feels bad for asking that Aki prompt Haru to join the medley because of this, he's reassured that it wasn't offensive, because much like him, she wants to see Haru join the medley too. They have a mutual respect for each other, connecting through their conversation about Haru, and are even able to joke around together.

In Aki's POV, she's shown to wonder over how he's always "running towards somewhere," seeking something.