Unlocked

Lee Na-Mi (Chun Woo-Hee) works as a marketer at a start-up company. She is an ordinary office worker who works hard everyday. She also works part time at her father’s cafe, Cafe Mizi.

One day, Lee Na-Mi loses her smartphone on the bus and it is picked up by someone. When Na-mi uses a friend’s phone to call, Oh Jun-Yeong (Im Si-Wan) uses a fake voice app to speak so his voice won’t be recognized, instructing her to pick up her phone at a repair shop. He does this so he can get access to her password and under the pretence of fixing her broken phone screen, he installs spyware on her phone.