I feel like I saw this story already and also wondering why it took so long for a K-drama version. K-actress Shin Hye Sun is in talks for a tvN fusion sageuk drama Queen Cheorin scheduled for November 2020 so plenty of ways away. It tells the story of a modern day man named Bong Hwan who time travels back to Joseon era and into the body of the Queen. It’s totally the C-drama Go Princess Go which aired in 2015 and made leads Zhang Tian Ai and Sheng Yi Lun famous. It was silly and entertaining enough to watch and I can totally see Shin Hye Sun in the role of the female lead with a male soul inside her body and needing the navigate historical times as well as palace intrigue. Queen Cheorin is from the PD of Hwarang and the screenwriter of Dr. Prisoner and Inspiring Generation.