The Kansei Reforms (寛政の改革, Kansei no kaikaku) were a series of reactionary policy changes and edicts which were intended to cure a range of perceived problems which had developed in mid-18th century Tokugawa Japan.
Matsudaira Sadanobu was named the Shogun's chief councilor (rōjū) in the summer of 1787; and early in the next year, he became the regent for the 11th shogun, Tokugawa Ienari. As the chief administrative decision-maker in the bakufu hierarchy, he was in a position to effect radical change; and his initial actions represented an aggressive break with the recent past.
Sadanobu's efforts were focused on strengthening the government by reversing many of the policies and practices which had become commonplace under the regime of the previous shogun, Tokugawa Ieharu. The broad panoply of changes and new initiatives became known as the Kansei Reforms.
Sadanobu's policies could be interpreted as a reactionary response to the excesses of his rōju predecessor, Tanuma Okitsugu. The result was that the Tanuma-initiated, liberalizing reforms within the bakufu and the relaxation of sakoku (Japan's "closed-door" policy of strict control of foreign merchants) were reversed or blocked.
This reform movement was accompanied by three others during the Edo period: the Kyōhō reforms (1716–1736), the Tenpō reforms of the 1830s and the Keiō reforms (1866–1867).
Chronology
The shogunate's interventions were only partly successful. Intervening factors like famine, floods and other disasters exacerbated some of the conditions which the shogun intended to ameliorate.