MakoHaru

MakoHaru is a slash ship between Makoto Tachibana and Haruka Nanase in the anime Free! Iwatobi Swim Club/Eternal Summer.

Canon
Makoto and Haru are childhood friends and best friends. Makoto often knocks on Haru's door in the morning to get him to get out of the bath and to go to school. They always walk to school together and have been on the same swim team since they were kids. They end up going to the same college.

Fanon
Makoto and Haru are practically married, usually loving and cute. Nagisa and Rei usually make a comment such as "I thought they were already dating." In fanfic.

Trivia

 * Haru's animal is a dolphin, while Makoto's is a Killer Whale/Orca.
 * Haru is obsessed with water
 * In the abridged series, 50% off, Makoto is shown to be in love with Haru.
 * Haruka likes to be called Haru in the anime