Sosuke Yamazaki/Story

Free!-Eternal Summer-
Sosuke enters the series as a character, serving as a counterpart to Haruka Nanase (quiet demeanor and exceptional talent), as well as a source of insight into Rin Matsuoka's past and character. His arc is a prominent part of the series's story.

He is first introduced under the guise of an antagonist, until Rin greets him fondly with a special handshake. Sosuke expresses his intimidating manner when he confronts Haruka several times about Rin's future prospects as an Olympic champion. Driven to the point of breaking and unable to use his talent, Sosuke's shoulder injury is the nail in his swimming coffin. His story arc points to Haruka's indifference to competition as something that could lead to the same end. Sosuke's blindness to what a team effort brings to swimming serves to show how teammates can improve through support from others, as well as demonstrate how strong the bond between the other characters has grown.

Sosuke serves as the main subplot of the season (and for certain episodes, the plot). He acts as a foil to Rin, as he is much calmer and more independent. His ending is one of acceptance: in regards to himself, his relationship with Rin, and his future with swimming. He realizes his swimming days are over, but that doesn't mean his friendship with Rin is, too. Throughout the season, he gains important relationships with the other members of the Samezuka Swimming Club, growing to care for them as he continues maturing as an individual.

Free!–the Final Stroke– the second volume
Sosuke participates in a four-swimmer relay at the Fukuoka Tournament with Rin Matsuoka, Ikuya Kirishima and Haruka Nanase. They take first place.＊

＊Translation Note: This information is gleaned from unofficial translations of media still in cinemas; ergo, all related facts may be subject to change/corrections in the future when official translations are released.