It is said that 'Kami' referred to the highest, 'Suke' to a deputy, 'Jo' derived from the pronunciation of 'Jo' (丞), the third-rank official of the government body in the Tang, and 'Sakan' derived from 'sakan' (左官), which means an assistant.
「かみ」は最上位を表し、「すけ」は補佐の意味、「じょう」は唐代に一部の官庁で三等官の呼称だった「丞」の借音、「さかん」は補佐官を意味する「左官」にそれぞれ由来するといわれる。