Sezon 1
Busan'da bir yetimhanede büyüyen Ok Chanmi, Seul'e evlat edinilen ikiz kardeşi Park Wonseok'un intihar ettiğini duyar. Chanmi, Wonseok'un kendini öldürdüğüne inanmıyor ve suçlunun hala okulda olduğuna inanıyor. Ancak, ne polis ne de Wonseok'u evlat edinen ailesi ona inanmayınca, Chanmi meseleyi kendi başına halletmeye karar verir.
Bölümler
Episode 1
Chan-mi transfers to her twin brother's school to find out the truth about his suicide.
Episode 2
Chan-mi learns a shocking truth of a different life that her brother lived.
Episode 3
Soo-heon punishes Sa Jung-kyung and is called a hero by the students, but Chan-mi grows suspicious.
Episode 4
There is a scheme to kick Chan-mi out of school, and Soo-heon advises her to leave.
Episode 5
Won-seok's case is reclassified as a homicide. Chan-mi learns of Won-seok's lie to her.
Episode 6
Soo-heon finds himself in a predicament as he becomes number one suspect of a murder.
Episode 7
Chan-mi gets an unbelievable call, as she holds Soo-heon at gunpoint.
Episode 8
Chan-mi and Soo-heon are convinced that Gi O-sung is Won-seok's killer.
Episode 9
Soo-heon revisits Sa Jung-kyung's camping car, but it is a trap.
Episode 10
O-sung feels betrayed as his plan fails. Chan-mi makes a shocking discovery as she sets up a trap.
Episode 11
Jae-bum regains his memories, but Soo-heon is unfamiliar with this version of Jae-bum.
Episode 12
As truths emerge, the time for the final revenge has come.