Try these, I think they match well with that you are looking for:
Eternal Love of Dream - He isn't shy but stays away from women,. It takes him a long time for him to warm up the the FL but she tries many ways to gain his heart. One thing that you may not like is that he is quite seductive as he begins to fall for her.
Go Go Squid! - ML isn't shy but doesn't concentrate on women, he takes a while to warm up to the FL. She has more of a bubbly personality but he is quite cold and doesn't talk about his feelings with anyone. He eventually warms up to her but he doesn't know how to show his feelings xD.
I Cannot Hug You - Shy and awkward ML and bubbly FL. Kind of a slow burn romance but not as slow as the dramas above.