The male protagonist is a masked prince.

It wasn't about transmigration. It was about a beautiful concubine who was like a fairy wherever she went. Then, because that prince was too handsome, he wore a mask everywhere he went. When he attended a banquet in the palace, he would open his mouth in the mask and drink…Because the male protagonist's own mother and the female protagonist's uncle had something when they were young, they thought that their father had been betrayed and now married the female protagonist to take revenge. He seemed to have locked the female lead with a small chain. Only he had the key to open it. I know the plot is very common, but please help me think about it ~ I don't have to watch it, but I have OCD and I have to remember which one it is... Later on, the female protagonist's brother (non-biological brother) wanted to bring her here. His highness locked her up somewhere in the backyard and then there was a fire. The female lead was very all-rounded, but the male lead did not love her at first and even pushed her off the cliff. Thank you, please think about it ~