In ancient times, there was a custom where Oshokuryo (side dishes excluding grain) including mainly fishery products were presented to the Emperor and the Imperial Family as sacrifices, and it is considered that, under the Ritsuryo system, this was stipulated in addition to Soyocho (a tax system).
古代においては、天皇・朝廷に海水産物を中心とした御食料（穀類以外の副食物）を贄（にえ）として貢ぐ慣習があり、律令制のもとにおいても租庸調などの税とは別に、贄の納付が定められていたと考えられている。