Princess Knight, also known as Ribon no Kishi is a Japanese manga series written and illustrated by Osamu Tezuka. This manga follows the adventures of Sapphire, a girl who was born accidentally with a blue heart of a boy and a pink heart of a girl. She pretends to be a male prince to prevent the evil Duke Duralumin from inheriting the throne of Silverland. The gender-bending main character was inspired by the all-female musical theater group Takarazuka Revue in which women performed both female and male roles.

Osamu Tezuka was a Japanese manga artist, cartoonist and animator. Born in Osaka Prefecture, his prolific output, pioneering techniques and innovative redefinitions of genres earned him such titles as "the Father of Manga" , "the Godfather of Manga" and "the God of Manga" . Additionally, he is often considered the Japanese equivalent to Walt Disney, who served as a major inspiration during Tezuka's formative years. Though this phrase praises the quality of his early manga works for children and animations, it also blurs the significant influence of his later, more literary, gekiga works.