In 1876, the Department of the Legislation proposed the plan of classifying kazoku into these three ranks, "Ko" "Haku" and "Shi," and this three-rank plan was mostly supported before Seinan War.
明治9年（1876年）には法制局が『公』・『伯』・『士』の3等級案を提出し、西南戦争以前は3等級案が主流となっていた。