Season 1
Seon Woo helps out Jang Il and his father Yong Bae, who are going through rough times because of loan sharks. Feeling grateful, Jang Il offers to help Seon Woo with his studies and they become close friends. But to help cover up Chairman Jin’s crime, Yong Bae makes it look like Seon Woo’s father committed suicide and knowing about all this, Jang Il tries to kill Seon Woo to prevent him from filing a petition and they become enemies. Having barely survived, Seon Woo loses his sight from the shock of the incident and pretends to have lost his memory in order to find the truth. With the help of Tae Ju, who pretends to be his father, Seon Woo is rescued from despair and reappears in front of Jang Il now as a successful businessman. Still receiving threats from Chairman Jin, Jang Il is flustered by Seon Woo’s reappearance and now Seon Woo’s revenge begins.
01. Episode 1
Seon Woo and Jang Il form a fast friendship, but when Seon Woo's father commits suicide, their friendship becomes marred with dark secrets.
02. Episode 2
Seon Woo tries to solve the mystery around his father's death. Jang Il's father tries to cover up his tracks.
03. Episode 3
Seon Woo and Jang Il both get closer to the truth about the death of Seon Woo's father, which drives them apart.
04. Episode 4
Seon Woo must live with a heavy conscience and fears the day Jang Il might regain consciousness.
05. Episode 5
Seon Woo struggles to function without eyesight, but he regains his memories - including those of Jang Il's betrayal.
06. Episode 6
Ji On and Seon Woo are reunited at a school for the blind and Jang Il grows increasingly frustrated.
07. Episode 7
The relationship between Ji On and Seon Woo continues to grow and Jang Il's father starts to receive blackmail letters.
08. Episode 8
Ji On's relationship with Seon Woo become complicated just as Moon Tae Ju steps into the picture to help his son.
09. Episode 9
Seon Woo must decide if he will break ties with his friends to leave with Moon Tae Ju, who claims to be his father.
10. Episode 10
After an extended stay abroad, Seon Woo is back in Korea as a new man, about to give his childhood friends a huge shock.
11. Episode 11
Jin No Sik and Jang Il both must tread carefully after learning the truth about David Kim's identity.
12. Episode 12
Seon Woo set his plan for revenge in motion and So Mi reveals to Jang Il a shocking secret that changes everything.
13. Episode 13
So Mi conspires to make Jang Il hers while Seon Woo moves forward with his plan to force Jang Il into an awkward position.
14. Episode 14
So Mi and her father are called in for questioning surrounding the investigation of Jin No Sik.
15. Episode 15
Lee Yong Bae must testify as a witness for the murder of Sun Woo's father.
16. Episode 16
Jang Il gives Sun Woo one last chance to ask for forgiveness before he launches his plan to destroy his life.
17. Episode 17
Sun Woo makes it painfully clear to all those involved in the death and cover up of his father that revenge is imminent.
18. Episode 18
Sun Woo receives the final pieces of the puzzle surrounding the identity of his biological father. Meanwhile, Jang Il's father breaks under the pressure.
19. Episode 19
Sun Woo devises a plot to oust Jin No Shik out of the company completely, while Jang Il breaks down as he sees his life falling apart.
20. Episode 20
Sun Woo's symphony of revenge reaches its final crescendo in this shocking finale filled with revelations and reconciliations.