Coffee Prince is the untouchable gender bender kdrama classic of them all---if not the best for most of kfans. This is set on the modern times, but the feels are the same, and both are executed very well. Love in the Moonlight has other plot points though like political intrigue, while in Coffee Prince the main plot is the gender bender.
Both are a good mix of romance, comedy, drama, fantasy, and supernatural. The actors are amazing. Ghosts/monsters also always find the heroine, and the hero helps to protect her. Each ghost case imparts some food for thought.
Both are kdramas about personal growth with friends through music. One is kpop though, and Cantabile is about classical music. Both have an adorable ragtag group of music students.