Based on Jo used for Kokushi under the ritsuryo system, the Imperial Court (Sagagosho during the Edo period, and branches of the imperial family after the Meiji period) gave the official title Jo to regular merchants, sword smiths, performers including Joruri performers and the like to honor their accomplishments in later generations.
律令国司における掾が転じて、後世、朝廷（江戸時代は嵯峨御所、明治以後は宮家）から、出入の商人や刀匠、浄瑠璃の芸人などに対して、その技芸を顕彰する意味で下賜された官名。