Princess Dia of the Diamond Kingdom is best known for being the shy, glasses-wearing princess who briefly became a person of interest to the forces of evil. She showed up in episode 22 of the anime and Act 4 of the manga, making her one of the rare minor characters to appear in both versions of the story.
The whole reason she caught anyone's attention in the first place was a crystal she owned—one that Luna and Queen Beryl thought might be the legendary Silver Crystal, which would have made her the Moon Princess. That alone was enough to make her a target. She was even possessed by Nephrite's Shadow at one point, though it didn't stick around long.
As it turned out, her famous crystal wasn't anything mystical. Depending on which version you're reading or watching, it was either a statue of herself or a statue from her kingdom's first princess. Either way, she definitely wasn't the Moon Princess everyone was looking for. The whole thing fizzled out pretty quickly once that truth came to light.
Content compiled by AnimeList.moe from publicly available sources.
