Based on 'taihon hippo (most writing techniques), i.e. tenkaku hattai (eight basic elements of characters) are included in character "永",' and 'happo (eight techniques) were created at the beginning of the use of reiji (Chinese characters written in the demotic semi-square style), and '八体 (eight shapes) which have been passed from Houhan's SAI Shigyoku via SHO and O to later generations are sufficient for ten thousands characters,' which are stated in Tang's CHO Kaikan, "Gyokudo Kinkei", a theory has been put forward for its origin that SAI En, SHO Yo, and WANG Xizhi initiated.
その由来には唐の張懐瓘『玉堂禁経』にある「大凡筆法、点画八体は『永』字に備わる」「八法は隷字の始めに起こり、後漢の崔子玉より、鍾・王を歴て以下、伝授し用うる所の八体は万字に該す」といった記述から崔瑗・鍾繇・王羲之説が唱えられてきた。