Ikuya Kirishima/Story

High☆Speed！－Free! Starting Days－
In High☆Speed！－Free! Starting Days－, Ikuya is known for the breaststroke and the middle school team swims a successful medley with Makoto swimming the backstroke, Haruka the crawl and Asahi the butterfly. The story of their coming together as friends and teammates is told.

Free!-Timeless Medley- the Bond
In the beginning of Free!-Timeless Medley- the Bond, it is shown that after Haruka Nanase quit the swim club, Ikuya got mad at him leading to a situation similar to the fight between Haru and Rin Matsuoka that made Haru quit the swim club. Towards the end of the movie Sosuke Yamazaki witnesses Ikuya swim at nationals and is clearly shocked by what he sees. Ikuya is then shown discussing his current swimming progress with his brother over the phone.

Free!-Timeless Medley- the Promise
In Free!-Timeless Medley- the Promise, Ikuya was shown in Sosuke's flashback during one of the competitions. The flashback shows Ikuya swimming the individual medley and winning, surprising Rin as he said that Ikuya was Haru's friend. Sosuke tells Rin about Ikuya, stating that his swimming is the same as Haru's.

Free!-Dive to the Future-
Throughout the third season, the reason for the rift between Ikuya and the rest of the middle school team is revealed. It is learned that due to problems between Rin and Haruka, Haruka quits the swimming team without a reason after only one year. This, despite giving Ikuya a promise that they would swim together again when school resumed in the Fall. Makoto leaves to support Haruka and Asahi moves to a new neighbourhood. Ikuya is hurt and disappointed and goes to America to study, train and be with his brother.

As he grows older, Ikuya works tirelessly to master all four strokes and becomes a strong competitor in the Individual Medley (IM). His crawl (or freestyle stroke), however, is noted to be similar in speed and style to that of Haruka. When Ikuya and Haruka meet again while at university, Haruka attempts to apologize but Ikuya brushes him off. Asahi and the others later realize that Ikuya harbors resentment towards them because of what happened in middle school. He wanted to have friends, be a part of a team and was inspired by Haruka to try freestyle; then everything was lost.

Ikuya's problems with swimming and his past are worsened by his many readings of the Hans Christian Andersen fairy tale, The Little Mermaid. Ikuya interprets the ocean described as a pure paradise beyond the world's problems, but has difficulty believing this because of his breathing issues. He likes mermaids because water is their natural environment but when, in the story, Ariel sacrifices ease in the water to gain human legs and is in constant pain, Ikuya relates to her. Metaphorically, he sees it as a message that he must walk in another environment and confront his demons if he wishes to move forward.