Japanese prisons are infamous for their tough conditions, and are regarded by some as a holdover from the days of the military dictatorship of the 1940s. Japan has yet to sign the UN convention against torture. The maximum penalty for cannabis is 5 years for simple possession and 7 years for cultivation or smuggling. Many of the arrested are reported to the police by concerned family members. Others are couriers from Southeast Asia or people who mail themselves drugs from abroad caught by customs.
Most smugglers caught do go to prison for several years.
Some foreigners from Asia or Africa who have overstayed their visas finance their stay selling hashish or marijuana. There has been some evidence of large scale smuggling involving hundreds of kilos of cannabis but hardly any arrests on that scale. Black market prices appear to range between 2000-3000 yen per gram, about half of the price usually quoted by police in arrest reports. Many Japanese pot smokers avoid the risky black market and its high prices by growing their own, starting from seeds obtained from Holland, Canada or Thailand. The Japanese climate is ideal for cannabis and Tokyo is on the same latitude as Afghanistan or Morocco.