Sure, Yaoi manga is very real. It typically focuses on romantic and sexual relationships between male characters. These mangas are created and consumed by many people around the world.
Give 'Given' a shot. It has beautiful illustrations and a touching plot that will keep you hooked. The relationships between the characters are complex and interesting.
Another way is to compare it with officially released versions. If there are significant differences in the story, characters, or overall presentation, it could be a fake manga.
A man of virtue yaoi manga often has intricate and complex relationships. It might have beautiful art styles depicting tender moments and inner struggles of the characters. Also, it could deal with social or personal obstacles the characters face in their relationship.
In my experience with Manga Master, there hasn't been any yaoi. It might have some similar themes or elements, but not full-fledged yaoi stories. It's mainly known for other types of manga content.