Mulan

Both movies are about a girl disguising as a boy. Both movies are directed by Jingle Ma. Both movies are based on famous classic Chinese tales.

Comedic film of a fusion-historical genre. Cute lover boy Heo Saek becomes Joseon's first male gisaeng and a flower-like woman named Hae Won who thinks ahead of her time, search for true love together.

Both are epic Chinese historical wuxia war movies. Both movies star Vicki Zhao as a kickass noble lady.......................

Both FLs disguise as men and join the army, becoming a general. Both MLs discover the FL's gender when they accidentally see her taking a bath.

Both productions have Chen Kun as male lead, accompanied by cross-dressing strong female lead. While one of them focuses more on fighting/action and the other one focuses on politics, they both showcase women who are good at their, seemingly male-only, job.

Both have a strong FL who disguises herself as male and a military ML who learns her secret early on but hides it for her.

I've read that the series were based on the 2009 film, it was daebak

Both films are about historical wars inspired by real events and old tales. They involve two great main female character – who by cunning and courage – saves their nation from hostile foreign forces. Willing to sacrifice themselves, they're selflessly fighting for what's important; to achieve lasting peace and to protect their country, and beloved people.

Both are telling the legendary story of Hua Mulan and how she went into the military in place of her father and became a great solider that sacrificed a lot for the safety of her homeland.

Both films are about historical wars inspired by real events and old tales. They involve two great heroes – who by cunning and courage – saves their nation from hostile foreign forces. Willing to sacrifice themselves, they're selflessly fighting for what's important; to achieve lasting peace and to protect their country, and countrymen. The movie Mulan, though, have elements of romance and a stronger fokus on friendship.

In 1867, Sin Jae Hyo leads the Dongrijungsa, which teaches pansori (traditional Korean musical storytelling). A young girl, Chae Seon, who wants to perform pansori, appears in front of him. Chae Seon has dreamed of performing pansori since she first heard Sin Jae Hyo perform when she was little, but Sin Jae Hyo turns her down because women are not allowed to perform pansori. Chae Seon then disguises herself as a man and enters the Dongrijungsa to learn pansori, but Sin Jae Hyo doesn’t accept her as his student. One day, he hears Daewongun, the most powerful man in Joseon and the father of the King, is going to hold a national competition of pansori performers known as “Naksungyeon”. Sin Jae Hyo decides to teach Chae Seon, who has a true voice to perform “Chunhyangga". If anyone finds out that Chae Seon is a woman, Sin Jae Hyo and Chae Seon will both face death.