Best definition
yoai
Anime/Manga term meaning Gay Pairing, invented by western fans. Yoai commonly means (in fanfiction terms) that there is more sexual

homosexual content, as apposed to shonen-ai which would be more clean.

Yoai pairings include – Yuki Eiri/Shuichi Shindou, Naruto/Sasuke, Edward Elric/Roy Mustang, etc