The Last Empress(2018)

Original title: 황후의 품격

In an alternate-reality South Korea, where a constitutional monarchical system prevails, Oh Sunny, a musical actress, becomes the empress of the country. Thus begins a dispute for power in the royal palace. Nothing is what it seems, and Oh Sunny is ready to fight until the end to uncover a mysterious homicide within the royal palace, fighting to protect those she loves the most and obtain happiness.