Shujikan were the predecessor of modern-day prisons created in the Meiji period. The chief of Shujikan was called Tengoku.
Starting in Kosuge (which was located on the site of today's Tokyo Detention House) and Miyagi (the predecessor of Miyagi Prison) in 1879, Shujikan were built across the country under the direct control of the Ministry of Home Affairs (Japan).
Due to mounting criticism of forcing hard labor on prisoners, forced labor was gradually abolished since around 1894, and Shujikan were renamed Kangoku and dissolved to form new facilities after 1903.
Shujikan in Hokkaido
In Hokkaido, more facilities were established per capita than in other areas because the reclamation of Hokkaido was an urgent need to counter Russia's southward expansion.
Shujikan was built at key places within Hokkaido, including Kabato (Tsukigata-cho Town), Sorachi (Mikasa City), and Kushiro (Shibecha-cho Town [the Abashiri prison was a branch of Kushiro Shujikan]), and prisoners were engaged in labor for reclamation. The prisoners were mobilized for road building in Kabato and Abashiri, and for the labor in coal or sulfur mines (in Mt. Atosanupuri and so on) in Sorachi and Kushiro. Kamikawa Road (present National Route 12) is renowned as the road which was constructed by the prisoners in Kabato Shujikan and Sorachi Shujikan.
Many of the first inmates at the Shujikan tended to have been imprisoned for ideological offenses; these inmates included fuhei shizoku (discontented former samurai) who had been captured during the Seinan War, and in later years, those who had been arrested due to their participation in the Kabasan Incident, the Chichibu Incident, and so on.
As for the reason why many Shujikan were built in Hokkaido, it has been said that there was an intention to keep prisoners to stay in Hokkaido after their release in order to increase Hokkaido's population which was fewer at that time. However, in fact prisoners did not contribute to the increase of the population because many of them died due to hard work or ran back to their hometowns after release.
Since many ideological offenders were locked up in Shujikan, it gradually attracted public attention, which resulted in the abolition of forced labor. However, in land reclamation projects in Hokkaido and at the labor site of coal mines in Kyushu (the Mitsui Miike coal mine in relation with Miike Shujikan), Takobeya (labor camp) Rodo, a form of labor under which general workers were placed in confinement and exploited to make up for the shortage of workforce, developed.