Any manga where girl turns into a man Or disguises herself as a man? it can also be the ot...

http://www.mangago.me/read-manga/from_today_on_i_m_a_boy/

"The villain discovered my identity" it's a manhwa tho

http://www.mangago.me/read-manga/kojinsa_arimasu/
http://www.mangago.me/read-manga/jun_and_kaoru/

"Prince Cinderella" is a good one, it's free on Lezhin. Please help support the author!