I don't think it is. Usually, such titles suggest fictional or semi-fictional content rather than being based on real events. There might be elements inspired by real life, but it's not a pure true story.
The meaning of 'af' in romance novels can vary. Sometimes it's just a part of modern - day slang that has made its way into the writing. Writers might use it to make their characters seem more relatable and contemporary. It could also be an acronym that the author has created for their own purposes within the story. For example, it could stand for a fictional organization like 'Alliance of Fairies' or something similar. It really depends on the context of the specific romance novel.
The length of DB mangas differs. It depends on factors like the story's complexity and the author's vision. Some might run for just a few volumes, while others could have dozens.