Soo-hyun, a fourth-year elementary school teacher, is about to get married. One day, Yohan, a student in her class, comes to Soohyun, who was busy and happy. Yohan confesses to Soohyun that he is experiencing domestic abuse. But the next day, John's lies await Soohyun.
Ji-O has a special power and a secret, but he doesn't know who he really is. He is chased by mysterious figures, while he tries to find answers to numerous questions that surround him. Goo-Reum is a detective. When she decides on a course of action, she won't change no matter what. Her parents disappeared when she was only a young child. Goo-Reum chases after the truth behind her parents' disappearance. She meets Ji-O and her life changes.
Nam Shin is a son from a family who runs a large company. After an unexpected accident, he falls into a coma. His mother Oh Ro-Ra is an authority on brain science and artificial intelligence. She creates an android named Nam Shin III which looks like just like her son Nam Shin. The android pretends to be Nam Shin and he has a bodyguard So-Bong.
Kang Woo Hyun is a respected anchor at a broadcasting station. He is a devout and happy father, who enjoys being surrounded by his charming family. He decides to try his luck in politics. One day, on a trip he makes with his family, a tragic incident happens. Meanwhile, Go Dong Kook, a veteran detective, who doesn't stop at anything until a case is solved, decides to take the case of Kang Woo Hyun and sets out to investigate what lies behind the tragic incident.
Noh Ji Wook is a prosecutor in the Central District Prosecutors’ Office who ends up switching professions to a private attorney. He harbors a trauma stemming from an event in his childhood involving his parents and his first love. Eun Bong Hee, a Taekwondo athlete in her youth, is a prosecutor trainee who has become a murder suspect. Eun Bong Hee and Noh Ji Wook both find themselves being the focus of a killer.
