Free Collars Kingdom(フリーカラーズキングダムFurī Karāzu Kingudamu) is a Japanese manga series written and illustrated by Fujima Takuya. The individual chapters were serialized in Magazine Z, and compiled into three tankōbon volumes released by Kodansha from February 2003 to March 2004. Set in Ikebukuro, Japan, the series revolves around the struggle of two stray cat groups. Cyan, a young newly-abandoned cat, joins one of them, the Free Collars. Each cat has two appearances; to humans, they appear as normal cats, but to other cats, they appear as catboys and catgirls. Each cat has their own attack, and some carry weapons.