In no Cho (院庁)

In no cho was the direct political institution of Daijo Tenno (the Retired Emperor) who took the reins of Insei (a cloister government) or the institution that handled shomusata (trial dealing with land-related issues) and zatsumusata (trial dealing with civil affairs) of Nyoin (woman bestowed with the title "in") in Japanese ancient and medieval period. Inshi (official of the In no cho) were responsible for practical work at In no cho.

In no cho of Insei

From the early Heian period, the Retired Emperor started to be called by ingo (a title of the Retired Emperor), and the Retired Emperor's immediate authorities, Toneri (palace servant) and Zoshiki (low-level functionary) were assigned to handle land management and routine tasks of the Retired Emperor called "In." The Retired Emperor's domestic governing institution was created by these Toneri, as well as other imperial families and dominant nobility. Sometimes the Retired Emperor's domestic governing institution issued monjo (written material), but most of them were about routine tasks. This domestic governing institution was called "In no cho." The first appearance of the term "In no cho" dates back to the reign of Emperor Uda.

When Insei that the Retired Emperor reigned as Chiten no kimi, a factual monarch, and performed government affairs started in the late Heian period, In no cho changed to an important political institution to express and embody Chiten's political wills. Innocho kudashibumi (letters), innochocho (orders) and inzen (decrees) issued by In no cho embodied Chiten's political wills.. Benkan (Oversight Department: division of the daijokan responsible for controlling central and provincial governmental offices) and Gekikyoku (Secretaries' Office) of Daijokan (Grand Council of State) were previously recognized as important institutions to issue emperors' imperial rescripts and official documents from Daijokan to local governments, but after Insei started, In no cho replaced those institutions. At first, In no cho meant only the Retired Emperor's domestic governing institution, but it came to mean Chiten's overall political institutions (broad In no cho).

Inshi belonged to In no cho. Middle-class nobles who had high business ability and had experienced Zuryo (provincial governor) were appointed as Inshi. This caused the political influences of upper nobles centering on Sekke (line of regents and advisers) to decrease. Furthermore, some of middle-class nobles including Inshi became Chiten's aides and exercised influences. They are called "In no kinshin." In no kinshin were not exactly constituent members of In no cho, but from the standpoint that they took part in political decision-making, they can be said to have created broad In no cho. In addition, Hokumen no bushi (the Imperial Palace Guards for the north side) and Saimen no bushi (the Imperial Palace Guards for the west side) were placed in the name of security at In no cho, which enabled Chiten to possess own military forces.

After the height of Insei from the Retired Emperor Shirakawa to the Retired Emperor Gotoba, In no cho continued to function as an important political institution of the Imperial Court (central government) until Insei lost substance in the early Muromachi period.

In no cho of Nyoin

After the system of Nyoin was established in the middle of the Heian period, In no cho, Nyoin's domestic governing institution, was established modeled after the Retired Emperor. When Insei started in the late Heian period, so many manors were donated to Chiten no kimi. Chiten let Nyoin inherit a huge number of manor groups, but in fact, In no cho of Nyoin (Nyoin no cho) covered operational management of these manor groups. Nyoin no cho also issued innocho kudashibumi and inzen dealing with matters mainly concerning Nyoin's manors.