In a rural farm village, a young boy named Hwayi is raised by five notorious criminals who serve as his fathers. When the group is hired to kill a man named Lim and his wife, the others sense something off about the job, but Suk-tae insists on completing it with Hwayi in tow. During the mission, Hwayi discovers a photo of a child in Lim's home, only to later learn that he is forced to kill him. After committing his first murder, Hwayi becomes ill and realizes the child in the photo bears an unsettling resemblance to himself.

Hwayi: A Monster Boy
A young person with a tumultuous family background finds themselves entangled in a deadly cycle of crime, compelled to face a dark and haunting legacy while committing a string of violent murders.