Strike Back

Lucy Heartfilia is a badass. She was bullied, but she solved that problem herself. She was adopted into a rich family, and these girls found out. So they bullied her about it. After she fixed the problem, she just started not caring at all. Her grades were still high, but she was not a good student anymore. So her adoptive parents kicked her out. With no where to go, Lucy wonders around for a few days, but at the time she is sleeping at a luxury hotel. She's rich, her family didn't cancel her cards.

Natsu Dragneel is a badass too. But he wasn't bullied. He was just always like that. He also happened to be a player. When he was younger his mother cheated on his father, and his father told him that all women are the same and will just cheat on him the moment they see someone else. So now he doesn't care about anyone's feelings and just uses the girls at his school for his own pleasure. Then after he dumps them and finds a new girl.

Lucy intruiged him because she didn't fall for him the first time they made contact. Lucy gets pushed into living with Natsu, and things get a little heated.