The Shishiki(Shishoku) represents the ranking or social status of samurai families in the Muromachi Period.
The Akamatsu, Isshiki, Kyogoku and Yamana clans, whose heads were feudal lords that ruled local territories as military governors, were known as the "Shishiki (or Shishoku)" clans (meaning "four top ranking clans") and the military police director (called "tonin" or "shoshi" in Japanese) of the Muromachi bakufu (Japanese feudal government headed by a shogun) was chosen from among these clans in turn in order to take charge of military leadership, law enforcement and tax collection in the city of Kyoto. In fact, however, the military police director was often also chosen from the Toki clan, a ruling clan in Mino Province, along with these four clans, which therefore needs to be included as a "Shishiki" clan.
Members of the Shishiki clans participated in political affairs of the Muromachi government as principal retainers of the bakufu along with the three clans (Hosokawa, Shiba and Hatakeyama clans) from which shugun's deputies were chosen. After the Onin War in 1467, several feudal lords, including Masanori AKAMATSU, were appointed as the military police director, but the post remained vacant for a long period of time and gradually disappeared from history as a result of battles in the Kinai region (areas around Kyoto) and the feudalization of land by powerful feudal rulers.