SouMako

SouMako is the slash ship between Sousuke Yamazaki and Makoto Tachibana from Free!.

Canon
The two interact very little in the series. The only time they have a one on one interaction is in the OVA when they discuss Nagisa's ability to coerce people into doing what he wants.

Fanon
Souske and Makoto tend to serve as a second focus couple in RinHaru fics.

Fandom
AO3

Trivia

 * Makoto's animal is a killer whale/orca while Sousuke's is a whale shark.
 * Makoto main stroke is backstroke.
 * Sousuke's main stroke is butterfly.