Narcotics and Psychotropics Control Law
Japan has four separate laws to regulate drugs. There is one for marijuana, one for stimulants, and one for opium. The remainder of all drugs fall under the category "narcotics and psychotropics". All of these laws were written in the 1950s, although some were revised in the Heisei period in accordance with the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances. Marijuana was unregulated before the American occupation of Japan; opium was banned during the Meiji Restoration, stimulants, most commonly methamphetamine, were widely administered to soldiers and workers in the 40's and 50's.
The restrictions laid out by this law are comparable to Schedule II of the Controlled Substances Act.