Can you recommend a romance novel about the male protagonist's dual personality?

The male protagonist had a dual personality. He was gentle and refined during the day and changed into a different person at night. The male protagonist's family used to be in the underworld, but later it was whitewashed into a company. The female protagonist's father used to be the male protagonist's subordinate. The male protagonist was sick or something and needed someone to take care of him. The female protagonist was sent by her father to be a maid to serve the male protagonist, but the male protagonist deliberately teased and made things difficult for the female protagonist.
The male protagonist's personality at night was very hateful. He often teased the female protagonist until she wanted to cry. Later, the female protagonist finally couldn't stand it and went home. The male protagonist brought his parents to the female protagonist's house to propose marriage.

Answer 1

I recommend "Dual Character Sweet Concubine" to you. The male lead is a demon king with a dual personality. Under his cold and feminine appearance, he hides a deep and pure love. The female protagonist was a revered God of War. The intertwining of fate had allowed her to travel from the modern era to the ancient times. The two of them went around in circles and finally fell in love. I hope you like my recommendation. Muah ~