Looking for romance dramas with this type of main male lead, but not your cold-type male lead. Something similar to It's Okay That's Love (w/o the mental illness part) or Master's Sun/Oh My Venus male lead.

Often, main male leads have a temper/anger issues, or very quirky and act out of place.

Good Morning Call

 anisstomoe:

how about black?

How is Black?  I haven't started it yet, but I do appreciate the same type of male lead as requested by the OP

Because This is My First Life

^ Thanks, I finished that one recently

Kill Me Heal Me may refer some part of what ur expecting

 FyreRayne:

How is Black?  I haven't started it yet, but I do appreciate the same type of male lead as requested by the OP

The first thing I thought of was Black.  Song Seung Heon plays a who different (cool) kind of role here.  I personally loved it.  

I tried starting black. For some reason I couldn't stay interested. In any case, I'm waiting for it to finish airing.

The one that is currently airing, Jugglers. The male lead (Nam Chi Won) is just like you described! Cold at first glance, but not actually. 

She Was Pretty 

You Who Came From The Stars