Nobody Knows (2020)

I'll Find You No Matter What & Doll with Six Wings (1x1)

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Young Jin and Soo Jung are close friends. One day, Young Jin ignores Soo Jung's phone calls, and Soo Jung is found killed by a serial killer. On her way home from the police station, Young Jin gets a phone call from the murderer of Soo Jung, and she warns him that she'd find him no matter what. Young Jin becomes a detective.