Just saw the Japanese romcom Hajimete Koi wo Shita Hi ni Yomu Hanashi with a male lead who is a real boss at work, but obsessive, jealous and shy concerning his love interest. The FL is completely oblivious to his romantic feelings. This painful process goes on for twenty years (!) Sweet and funny story.
The still running show Her Private Life has a sturdy, protective guy who's in love with the FL since their schooldays. He's too shy to admit this, even to himself, pretending he's only caring for her like an older brother, but he gets very jealous when the ML enters their life.
Advance Bravely is a BL story, so there are two male leads. The older ML fits the description. He's the silent type, strong, protective, but moody/jealous/irritated with girls who seek the attention of his friend.
The Korean movie Mischange is about a lawyer with severe shyness. He has a secret crush on a girl for 10 years and she doesn't even see him until a miracle happens that enables him to swap bodies with his good looking colleague (mature love scenes)