Princess Knight (1953)

In the country of Goldland, it is prohibited to have a princess succeed the throne. When the queen has a daughter, she decides to raise her as a boy, and have her identity be a secret. However, Sapphire would occasionally don girl's clothes.

One day, disguised as a girl, Sapphire meets Franz Charming, a prince from another country. Not knowing the truth of her identity, they fall in love.

However, Duke Duralumin, a distant relative to Goldland's king, is plotting to overthrow him...

Note: Different from the 1963 version that was serialized in Nakayoshi. This version is shorter and does not include characters like Captain Blood.