To sum it up in one sentence: The Demon King had a younger brother, traveled through time and space earlier than him, and through a yin and yang mistake, he replaced his older brother and became Paulufram's fiancé.
Ps: The protagonist is an iceberg, only melting towards family and friends
Question: A slap on the left cheek means marrying the other person, but what about a slap on the right cheek?
Answer: It's @#￥%&*@#￥%&*
For answers, please read the article