Sousuke Yamazaki is a fictional character of the anime series Free!. He made is first appearance during the second season, Free! Eternal Summer. Sousuke is Rin childhood friend. Like is friend, he is part of the Samezuka Academy swim club. In the relay competition he swim in butterfly style. However, Yamazaki is really ambitious and that cause he some trouble, he train so much that he badly hurt is shoulder, but since he is stupid and wanted to swim with his best friend again, he came back to the swimming competition damaging his shoulder a bit more. Congrats Champ!! You are stupid.
Must say at first I was really fond of Sousuke, his way of treating Haruka make me have some cold feeling toward. But thanks to the Eternal Summer special and the thousand GIF of him smiling/laughing on Tumblr that whale shark become likable.
Of course I know why he was acting like this with Nanase, he wanted to be sure Rin had is change to get selected by some prestigious swim team.
If Rin, is the Haruka of Samezuka, Sousuke is the Makoto of Samezuka. Except he doesn’t look like cinnamon roll, he look more like he could kill you.