The Tokugawa gained dominance because of the large amounts of rice grown in the Kanto plain. This was food for samurai, not for peasant farmers. Therefore it seems likely that expensive sake was the drug of choice of samurai while peasants might have used cheaper hemp to relax. Both Chinese and western medicine used cannabis for healing. Cannabis was in use as a herbal medicine in China for some 5000 years.
Psychoactive strains exist particularly in Southern China, near Vietnam and Thailand.
The central Asian part of China bordering on Turkmenistan was a hashish exporting region until the 20th century. In Western countries cannabis came into medicinal use from the 1830s. Cannabis extracts were sold in pharmacies until the 1940s or 1950s. Countries like Britain and Germany imported seeds of psychoactive cannabis strains from India or Africa to grow medicinal plants. Such medicinal plants were also cultivated in Japan.