Uchuu Kaizoku Mito no Daibouken: Futari no Joou-sama
Aoi was raised as a normal boy on Earth. Little did he know he was the heir apparent to Mito, the Queen-turned-Space-Pirate of an alien race that chooses their sex at puberty! Aoi fell in love with Mutsuki, the police officer who was chasing Mito, and the three of them saved the Universe. The only side effect was that Aoi blossomed into a beautiful young woman.