White paper on crime 2010 Part2/Chapter4
There are three types of penal institutions, namely prisons, juvenile prisons, and detention houses. Prisons and juvenile prisons are mainly used to hold sentenced inmates while detention houses are mainly used to hold inmates awaiting judgment. Workhouses in which offenders who are unable to pay fine or petty fine are detained, and, except for some institutions, Kanchi confinement houses in which persons subject to court-ordered confinement (Kanchi confinement) under the provisions of Article 2 of the Act on Maintenance of Order in Courtrooms, etc. (Act No. 286 of 1952) are detained are attached to penal institutions. As of April 1, 2010, there were 77 main penal institutions (62 prisons that include four rehabilitation program centers, seven juvenile prisons, and eight detention houses) and 111 branch penal institutions (eight branch prisons and 103 branch detention houses).
Females aged 20 or older placed under guidance dispositions for committing the offenses stipulated in Article 5 of the Anti-Prostitution Act (illegal solicitation, etc.) are held in women's guidance homes. At present there is one women's guidance home in Tokyo, with only one female having been admitted (in 2005) to it over the last 10 years (Source: Annual Report of Statistics on Correction).