She is a princess of the Celestial Clan, and an accident sends her into the mortal world.
He is a disciple of the Demon Clan, and a great battle sends him into the human realm.
They meet on Peach Blossom Mountain. She treats his wounds and cares for him until he recovers.
In the peaceful mountains, they fall in love. But the arrival of the Celestial Emperor and the intrusion of a demon princess force them apart.
They love each other but cannot be together, becoming each other's deepest regret.
To become worthy of her, he makes a name for himself in the Demon Clan. After overcoming countless hardships, he becomes the Demon Lord.
He goes to the Celestial Palace to ask the Celestial Emperor for her hand, but is cruelly rejected. In a fit of rage, he plots the emperor's death.
When she learns what happened, she is consumed by grief. She leaves him and ends her own life.
Only then does he come to his senses, realizing that nothing matters more than her. He leaves the Demon Clan and goes to the human world.
