i was at karaoke and during the video on the tv it was showing a movie which looked like it was staring kwon sang woo. his character looked like some kind of mechanic and then he gets into a fight with a group of guys then beats them up. then i guess he went a little too far and went to jail/prison. while he went into his cell, he drops a baseball. get into it with a boss guy in his cell and later on they turn out to become closer. he gets out and looks for some girl he likes...

can someone help me figure out what movie this is?

Sounds like the movie Sunflower....It\’s really good! One of my favorites

http://www.koreanmovie.com/Sunflower_km396/

Bump

Sorry, I know this is really old but I\’m curious to know the name of the movie/drama series as well. I saw the clip today at a karaoke place too, exactly as described by the OP.