Hi guys!

I watched a korean movie a few years ago and I can't remember the name. It's a comedy. It was about a man, he was a bachelor. One day this girl shows up at his door with a little boy and a guitar. It turns out she's his daughter. And somewhere near the end of the film the daughter enters this singing competition.

I hope this was specific enough. I wish I could give the name of an actor.

Thanks for the help!

Speedy Scandal, maybe? (I haven't watched this movie myself, so I'm not really sure about the singing competition part.)
You're right, it sounds like Speedy Scandal. There is a singing competition at the end that the daughter enters into at his radio station.
I have similar question but about kdrama. My sister showed me some years ago one where there was a rich girl (probably an actress) and her bodyguard from a very poor neighborhood. I also remember that she really liked vistiting him and sitting with him in his arbor. I know that this description suits to many dramas but I hope that somebody will help me! :)
It sounds like That Fool http://mydramalist.com/371-that-fool

She's an actress and he's not her bodyguard, but he's faking being her boyfriend. The part that sounds like it might be That Fool is sitting with him in his arbor. IIRC that was a big part in the drama, like where she first falls in love with him.