高知市を中心に飼育されてきた事から土佐金と呼ばれており、高知県の天然記念物です。大阪ランチュウと琉金の交配によって生まれました。

This variety is called Tosakin because it has been bred mainly in Kochi City (Tosa being the former name of present-day Kochi), and is designated as a natural treasure of Kochi Prefecture. It was a result of crossbreeding between the Osaka Ranchu and the Ryukin.