Definitely recommend Gokusen and Crows Zero, not much romance in those though...
- Itazura na kiss (which has its own version on various asian countries)
- Good Morning Call (kind of similar to itazura na kiss)
- Yankee-kun to Megane-chan (the guy was not that bad but he was a rebel, very funny as well)
- Ikemen desu ne (which is the japanese version of You're beautiful)
- Kanojo wa Uso Wo Aishisugiteru (Movie. Also, he wasn't exactly bad but more like the tough guy who has no interest in life, kind of like the boy in tatta hitotsu no koi.)
- Nodame Cantabile: DEFINITELY recommended. It is long though... A Korean version was made a couple of years ago but I might say japanese version is funnier ¿?
- Shiritsu Bakaleya Koukou: School of bad rebel guys VS school of nice intelligent girls :D
- Yamato Nadeshiko Shichi Henge: 4 guys living with 1 girl.
- Atashinchi no danshi: many good looking boys living with 1 girl.
- Dokushin Kizoku
- Close Range Love (movie)
- Kyou, Koi wo Hajimemasu (movie)
- Himitsu no hanazono
- Heroine Disqualified (movie), it is not really that the boy was "bad" but it was a one sided love and it is really nice and funny.