Princess Knight

Once known as a skilled fencer who had masqueraded as a prince in order to succeed her late father, Sapphire is now happily married to her love Franz and queen of their combined realm. After she gives birth to twins, a boy and a girl who are now equal in the royal line of succession, however, a dispute arises among the courtiers and populace over which child is the true heir. When a whimsical cherub with a familiar face is unwisely summoned to settle the matter, he allows sheer luck to rule in favor of the boy. Yet once Prince Daisy is whisked away by a cabal opposed to his ascension, the remaining Princess Violetta must embark on the same path her mother once tread to safeguard her family’s claim to the throne. Cross-dressing is hardly the end of it as she undertakes breathless adventures with a gypsy lass she meets—Emerald! (Source: Kodansha USA)

Taking place in a medieval fairy-tale setting, Princess Knight is the story of young Princess Sapphire who must pretend to be a male prince so she can inherit the throne (as women are not eligible to do so). This deception begins as soon as she is born, as her father the King announces his baby is a boy instead of a girl. The reason for this is that the next-in-line to the throne, Duke Duralumon, is an evil man who would repress the people if he were to become king, and because of this the King will go to any length to prevent him from taking over. (Source: Wikipedia)

A reboot of Princess Sapphire currently running in Tezucomi, an 18-month special magazine commemorating Osamu Tezuka for his 90th Birthday.

The May issue of Akita Shoten's Bessatsu Shounen Champion magazine revealed on Monday that Spanish artist Kenny Ruiz (Telémaco, Dos Espadas) will launch a new manga in collaboration with Tezuka Productions based on various characters of Osamu Tezuka's manga. In the manga's story, a robot alliance rules over 90% of the universe. The knight Sapphire is troubled over the pain of non-robots, and she makes a decision, for a new future. (Source: Anime News Network)