Princess Sapphire is born with a girl’s body and a boy’s mind due to an angel’s mischief. Because her kingdom lacks a male heir, she is raised as a prince. Evil ministers attempt to expose her secret, but she refuses to tolerate the kingdom’s cruel conduct. Disguising herself as the “Princess Knight,” she wields a sword of justice to fight injustice. This animated adaptation of the original girls’ manga follows her romance and adventure, and it was the first television animation in Japan specifically aimed at a female audience.