Kaeru Yanagiya

Nikkatsu Roman Porno, the second entry in the Maruhi Oo'oku Gaiden series. Recieving a mysterious foreign love potion, the Shogun's harem (or Oo'oku) becomes disordered; meanwhile a famous woman attempts to enter and seek revenge in the disguise of a male monk.

When a wastrel son of a merchant stumbles upon a robbery he discovers that both thieves are women. When he confronts one of them she distracts him with her breasts as the other knocks him out. He falls in love and searches for the pair.