When Gu-won remembers his life as a human, he finds out why and how he was turned into a demon.
Gu-won has been living as a demon for 200 years now. He used to be a human before he became a demon, but he does not remember anything from his past.
When Gu-won meets Do-hee, he starts becoming human again. As a result, he loses his powers for a while.
His love for Do-hee makes him experience human emotions and triggers the memories of the life he has forgotten, reminding him of how he lost his humanity.
Yi-sun and Wolsim’s story
Gu-won’s past comes back to him in a dream. He sees himself as Seo Yi-sun, a man from a prestigious family well-known to everyone in his village.
Yi-sun neglects his studies, but his father never reprimands him because he is his only son and Yi-sun lost his mother at a young age.
One day, he comes across a courtesan, Wolsim, practicing sword dance. The courtesan is none other than Do-hee.
Wolsim is an intelligent woman and a talented dancer. She has just moved to Yi-sun’s village, and after their first meeting, Yi-sun is taken with her.
Yi-sun keeps going to the same place every day in the hope of meeting Wolsim again, and he is not disappointed.
With time, Yi-sun and Wolsim fall in love. Yi-sun wants to marry Wolsim, but Wolsim knows that it is not possible given the difference in their social classes.
Wolsim’s past experiences have taught her that love only makes one miserable, and she warns Yi-sun of the same, but Yi-sun does not give up hope.
Yi-sun’s introduction to Catholicism gives him hope of overcoming the class divide that separates him and Wolsim.
Yi-sun and Wolsim both start attending meetings with the Catholics to learn about the faith that teaches all humans are born equal.
The loss of Yi-sun’s humanity
Yi-sun then decides to appear for the state examination, as he wishes to change the world. He gives a cross necklace to Wolsim before leaving the village.
At the same time, those who feel threatened by the teachings of the Catholics start attacking the people who associate with them.
Instead of watching the whole village burn, Yi-sun’s father decides to sacrifice Wolsim, claiming she is the only Catholic in their village.
Even at death’s door, Wolsim does not put Yi-sun in danger. She never tells her attackers that the cross that she wears was given to her by Yi-sun.
By the time Yi-sun returns to the village, it is too late to save Wolsim. Yi-sun can do nothing but watch her die and blame himself for introducing her to Catholicism.
The desire for revenge for Wolsim’s death drives Yi-sun to kill every single person present there, even those he cares about.
Yi-sun then takes his own life, refusing to go to Heaven, God’s residing place. At the time of Yi-sun’s death, God needed a demon in Hell.
Yi-sun’s grudge against humans made him the perfect candidate, which led to him being born a demon named Jeong Gu-won.
Also Read: Kim Se-ra: My Demon character explained
