Anime a popular roman in Japan .
And perhaps the most followed category of anime is Yaoi anime.
This manga written by women for describing homosexual relationships between men.

Yaoi, audio or visual work,about a romance or sexual relationship between two or more males. This kind a story primarily intended for a female audience.
Yaoi anime, one of the categories included in BL category (boys love). Another category included in BL is Shounen Ai.
The narrative of the Shounen Ai category  based on the emotional aspects of the relationship .
The stories in the Yaoi  explicitly describes the sexual relationships between the protagonists.
Much of the Yaoi characters are men in relationships with men attributed female attitudes and women’s social roles.
Yaoi basically a romantic story. But instead of the usual scenario(boys and girls),here are only boys, and many sexual scenes.

Yaoi a subgenre of Boy’s Love (called BL). That focuses very heavily on erotic and pornographic scenes, than any other part of the story elements.