Black Jack is a Japanese manga series written and illustrated by Osamu Tezuka in the 1970s, dealing with the medical adventures of the title character, doctor Black Jack. Black Jack consists of hundreds of short, self-contained stories that are typically about 20 pages long. Black Jack has also been animated into an OVA, two television series and two films.

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.