As a wise and powerful emperor, he did not allow his secret to be discovered by anyone... Until one day, he planned to tell his beloved girl his biggest secret... The emperor was a half-demon and could transform into a cat. The heroine has a golden finger. 1V1, double clean. Make assumptions about dynasties without research, don't delve into them, beware of those who make mistakes.
(It may not reflect the fantasy elements at first, but it will be sorted out gradually.)