I really like romance with delinquents. Examples Really like school 2013 with the hinted romance with the main guy and girl Also in monstar with the cool guy and nana. Oh and main male mc Has to be NON of these - childish -playboy
I can recommend Tatta Hitotsu No Koi.
MARS? maybe, maybe not. >_<
The best drama that I could think of and it perfectly suits your description is: Yankee-kun to Megane-chan; it's a school drama with delinquents and some romantic moments thrown every once in awhile but it doesn't focus on romance.
Shut up flower boy band if you haven't seen it is perfect for what you are looking for