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.
Yes. In some yaoi mangas, the plot begins with the characters being best friends and then progresses into a romantic relationship. It adds an interesting dynamic to the story.
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.
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.