Hae-young is a hopeless girl. She lives with her father who runs a Chinese restaurant, and a younger sibling. One day, her father has a mysterious accident, which places her in a position of responsibility. She is now not only the head of the house and must look after her younger sibling, but also an investigator tasked with finding the truth about the accident, and a fighter standing against the ugly world.
After being appointed as the vice-principal of her alma mater, Eun-hee becomes plagued by hallucinations. Branded a troublemaker by the teachers, Ha-young hears strange sounds coming from the school's dilapidated restroom.
Soo-jin, who lost her memories due to a horrible incident, starts suspecting her husband. She is confused between reality and illusion, truth and lies.
A struggling restaurant owner, caring for his sick mom, finds a bag of cash in a sauna locker, while a customs officer gets into trouble when his girlfriend runs off with money he borrowed from a loan shark.
Major crimes unit detective Seong-jin arrests Tae-sung for petty crimes, but shocked to find out that he is the notorious serial killer. However, Seong-jin becomes doubtful of his identity as the serial murder case is investigated.
A serial killer murders a girl from his neighborhood. The residents begin to suspect him one by one, as he tries to cover his tracks and plans another kill before escape.