I understand making girls rare to drop, and that's okay even if it takes me a week or two to get one. Dropping the EXP you get from fighting just seems like too harsh a penalty though. Its not enough that I'm still trying to get my first dark lord girl at lvl 16 I now also only get 1xp per fight to really rub it in. Like other people have suggested having a running counter that increases your chances of dropping a girl the more you've fought without getting one or at least making it so fighting isn't a complete waste of time would be good.
Other than that, I'm enjoying the game