He established the 'Oniwaban' (the shogunate's guard of the inner garden) (ninja [professional spy in feudal Japan highly trained in stealth and secrecy]) for the first time as shogun in order to supervise domains and rebellions.
将軍として初めて「御庭番」（忍者）を創設し、諸藩や反逆者を取り締まらせた。