Bang Jun-Ho

A karaoke in a rural town called "Karaoke Crazies" is run by Sung-wook. Business is slow and when Sung-wook posts karaoke singing along job to boost sales, a girl in early 20's, Ha-suk comes along. She's hopeless game addict and lack of talent but soon she starts to use a special tactic to lure customers in. Just when they are ready to come out of shade, little do they know that a serial killer on the loose in town is after something in the karaoke (imdb)