Just as the title, where female lead is disguised as a boy/man. Prefer to have a little romance, and would be good if had a military aspect like Empress Ki or Hua Mulan... don’t mind if C/Kdrama etc. THANK YOU  x :)

  • Hana Kimi / To the Beautiful you / Hanazakari no kimitachi e
  • Ouran High School Host Club
  • Ikeme desu ne / You´re beautiful
  • Coffee Prince
  • I will never let you go ( 2nd FL)
  • Black Butler ( violent) 
  • Oriental Odyssey 
  • Shine or Go Crazy ( after first few episodes she for in disguise)

Sungkyunkwan Scandal (girl disguise herselfe to enter the univ. - Hostorical/Romance)

The best historical drama I've seen with a girl disguised as a boy in the military is Oh My General (2017) . The love story is so cute. This girl goes all the way in her act, living the life of a general, with several concubines. Also there's another girl who's deeply in love with her.  Beautiful soundtrack as well. The English sub version is still on YouTube.

A bit like Empress Ki but much lighter is My Bratty Princess (2005). This Chinese series is about a girl dressed like a boy traveling with a street gang.  She meets the emperor in disguise.  Also she doesn't know  she's a princess herself. Starring Korean actress Jang Na Ra. Still available with English subs on Daily Motion and Drama Cool.

Furthermore MyDramaList uses hashtags that present drama titles like cross dressing.  Or try these custom lists: Gender-Benders: Girls in Disguise and Cross Dressing in Asian drama and movies. Enjoy!

I'm shocked no one mentioned You're Beautiful 

You’re Beautiful is mentioned in the first answer by  @Fanita

  • Hana Kimi / To the Beautiful you / Hanazakari no kimitachi e
  • Ouran High School Host Club
  • Ikeme desu ne / You´re beautiful

Mentioned by fanitha

  • Black Butler --Mentioned by Stevie70

And i will ADD

Tempest-Historical Drama where woman disguises herself to get educated and becaomes paer tof the roayal court right as the black ships come