However, entering the Heian period, the following custom began to be employed: When there was a Sangi (councilor) while being a legislator, was awarded with a small number of shikifu (or fuko) (families that the Sangi could control), he was appointed to kokushi as well, with his yonin approved, (called sangikenkokusei - literally, the system in which a Sangi was allowed to assume a kokushi as well).
しかし、平安時代に入ると、弘仁年間には議政官にも関わらず職封（封戸）が低かった参議に対して国守との兼務・遥任を認める例が慣例として現れた（参議兼国制）。