Need help to identify a korean indie movie title?

I saw it a couple of years ago but I forgot the name of it. It's about a mute guy who hides behind other people and he one day finds a girl he falls in love with. But she lives with her abusive husband. The movie ends with he living with them too, but since he is so skilled of hiding behind people and imitate their moves, he concealed himself and the girl is happy having him around in the house.