Oh, 18 and up all the way.
And it's not meant to have sex at the focal point. It's more like Ultimate Submission if you've ever seen it. 85-95% combat, 5-15% sex. Even then the sex will range from humiliating the loser to whipping with crops to actual sex.
It's also planned to be character driven. If you ever seen Debbi's diary from foxyfighter.com and how her stories detail how she got into fighting, what she's been up to, stuff like that.
An overview of the plan is as such. Established league in a fictional city where women perform wrestling (Pro-Style, but non-scripted) with the winner dominating the loser at the end. A young woman sees it for the first time and decided to get involved, and the story would focus on her both winning and losing, and what she does to the losers and what's done to her by the winners.
A portion of the charcters will also have certian fetishes they play to/like. The main character, for example, will be an exhibitionist. Another girl will have a thing for boob torture. Another will be a dominatrix who likes to spank and crop girls. Another who likes to give pleasure to the point it hurts.
I just wanted to pitch the idea here first since I didn't know if sex at the end would be frowned on or not.