Sekisho (Barrier Station) (関所)
Sekisho (barrier station) were facilities installed at the important points of traffic, in order to collect taxes and perform inspections. Sekisho were also referred to simply as "seki" (barriers). Those barrier stations installed along overland routes (roads, highways) were called "road barriers," while those established along sea trade routes were called "sea route barriers." Most of the barriers on overland routes were installed at mountain passes or rivers.
Barriers in ancient Japan
Even from its most ancient times Japan already possessed the system of barrier checkpoints; among the barriers of ancient Japan, three, namely the Suzuka-no-seki barrier along the Tokaido Road, the Fuwa-no-seki barrier on the Tosando Road, and the Arachi-no-seki barrier along the Hokurikudo Road, were considered especially significant given their intended roles of guarding the entrances to the Kinai region (the central region around the capital), and were thus termed the sangen (the three major barrier stations). All the land east of the three major barrier stations was called either Togoku (the Eastern lands) or Kanto (literally "east of the barriers"). From the mid-Heian period onwards, the Ausaka (Osaka) no seki barrier replaced the Arachi-no-seki barrier as one of the three major barrier stations.
In addition to the three major barrier stations, several other barriers were also erected, including: along the Tokaido Road, the Ashigara no seki Barrier on the border of Suruga and Sagami Provinces and the Nakoso barrier on the border of Hitachi and Mutsu Provinces; along the Tosando Road, the Usui-toge Pass Barrier on the border of Shinano and Kozuke Provinces and the Shirakawa-no-seki Barrier on the border of Shimotsuke and Hitachi Provinces; and along the Hokurikudo Road, the Nezumigaseki Barrier on the border of Echigo and Dewa Provinces. Among these various barriers, the Nezumigaseki, Shirakawa, and Nakoso Barriers were known as the 'Big Three Barriers of the Ou region' (Mutsu and Dewa).
Barriers in the medieval period
During Japan's middle ages, powerful and influential families or other groups, including the Imperial Court, the various warrior governments, lords of private estates, and powerful temples and shrines all established their own dedicated barrier stations, levying a "barrier toll" (also known as a "passage tax") at such barriers in order to make money. During the Muromachi period, the seven barriers of the Kyoto nanakuchi (seven roads into Kyoto) were erected, leading to a state of affairs in which anyone entering Kyoto would have no choice but to pass through one of the barrier stations.
During the Sengoku Period (Period of Warring States) (Japan), the sengoku (warring) daimyo ruling the various parts of Japan intensified their complete proprietary control over their own domains, and as a result the barrier stations that had been erected by all the various influential players lost their significance, and gradually fell into decline. Nobunaga ODA and Hideyoshi TOYOTOMI, who between them accomplished the task of unifying the whole country, completely and thoroughly abolished the barrier checkpoint system.
Barriers during the early modern and modern periods
In the Edo period, the Edo bakufu (Japanese feudal government headed by a shogun) and the various domains re-established barrier checkpoints, as they were necessary for military and police purposes. Important barrier checkpoints included, the Hakone-no-seki, Arai-sekisho and Suzuka-no-seki Barriers along the Tokaido Road, the Usui-sekisho and Fukushima-yado Barriers along the Nakasendo Road, the Kobotoke-sekisho Barrier along the Koshu-kaido Road, and the Kuribashi-yado Barrier on the Nikko-kaido Road.
The above mentioned barrier checkpoints were not under the direct control of the bakufu, but rather were entrusted to the supervision of nearby daimyo, hatamoto (shogunal vassals) or other such figures.
The status of the guards at the barrier checkpoints was baishin (indirect vassal), but in fact such guards came to wield enormous influence due to the fact that passersby, under the guise of giving "tips," were made to pay passage fees despite the fact that the guards were shogunal officials.
Anyone wishing to pass through such barriers would first have to present a checkpoint passage license to the checkpoint, and then received the confirmation from the checkpoint staff. Restrictions on allowing women and firearms to pass were strict, particularly at the barrier checkpoints along the Tokaido Road from Edo on westwards.
These were collectively known as the restriction on "letting in guns and letting out women," referring to the severe limitations placed by the bakufu on two things, namely the ability of the wives of daimyo stationed in Edo to return in secret to their own territories, and the influx of guns into the Edo region, the latter of which might render military action against the bakufu feasible (In a children's song, "Toryanse" [Ain't gettin' by!].)
Also, such as entertainers and sumo wrestlers, gave performances of their skills in lieu of paying for checkpoint passage licenses. Sekisho yaburi (breaking or sneaking through a barrier checkpoint) was considered a serious crime, and was punished by crucifixion. In reality, however, sekisho yaburi is said to have been fully normalized throughout the post stations with the collusion of the checkpoint officials.
The barrier checkpoints in Japan were completely abolished in 1869.