A kid finds out he's actually the heir to a space pirate queen, falls in love with the cop hunting her down, and transforms into a woman in the process. The show treats this not as spectacle or punchline but as the emotional ground of everything that happens next. Romance isn't the subplot here, it's the reason any of this matters, the thing that makes saving the universe feel like a smaller problem than figuring out who you actually are when your entire identity just flipped.

Aoi grew up on Earth as an ordinary boy, never suspecting he was the heir of Mito, a queen who became a space pirate and who belongs to an alien race whose members pick their sex at puberty. After Aoi, Mito and Mutsuki, the police officer who had been pursuing Mito, saved the universe together, Aoi emerged as a young woman. Now a hostile being who calls herself the rightful Queen of the Universe arrives, strong enough to wipe out whole planets. To protect her newly claimed throne, Aoi needs Mutsuki at her side, and Mutsuki must first sort out her own feelings for Aoi before the two can defend Earth and become the galaxy's first royal pair of queens.