Follow Your Heart.

While secretly investigating a case, Jiang Xinbai, a proud prince and the head constable who suffers from face blindness, accidentally meets the unorthodox Yan Nanxing, a female doctor who changes her appearance every month. They were at odds when they met and in order to keep their respective secrets hidden, they experience "three marriages" and "three separations" together. The two eventually join hands to eliminate the scourge of Wuxiang.