Kaguya-hime no Kakushigoto

In the Heian period, there was a princess whose beauty was exquisite enough to attract even the emperor. She was Princess Kaguya. What will become of an orphaned girl named Tsubaki when she finds out the ridiculous secret that the super famous princess was actually a man who came from the world above?!

(Source: Hakusensha, translated)

Included one-shot:
Volume 2: Kaeru-hime no Melancholy