Set in the 18th century, the show follows the Shogun Yoshimune, who likes to disguise himself as a low-ranking samurai and go into his capital of Edo to see the life of the common man, as well as to seek out and punish evildoers who would hurt his citizens. He is aided by Magistrate Oo'oka and a vivacious fireman, Tatsugoro, as well as a rotating cast of other recurring characters.

Along with Zenigata Heiji and Mito Kōmon, it ranks among the longest-running series in the jidaigeki genre. Like so many other jidaigeki, it falls in the category of kanzen-chōaku, loosely, "rewarding good and punishing evil."