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 20s, Ha-suk comes along. Shes hopeless game addict and lack of talent but soon she starts to use a special tactic to lure customers in. Then Na-ju, a professional singing along helper insists to help and she is like a savior, turning up the miserable place with her bubbly character. 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.