Those at the three posts took an oath of allegiance and fair administration to Emperor Meiji by putting their pledge called 'Sanshoku meiyaku' and 'Yakusoku shijo' into effect to the emperor.
三職は明治天皇に対して「三職盟約」・「約束四条」と呼ばれる誓約を行って天皇への忠誠と公正な政務を誓った。