Mito Koumon is the longest-running and most famous historical drama series in Japan with over 1000 episodes, which began broadcasting on Aug. 4, 1969, and continues today. Its main character is based on Tokugawa Mitsukuni, the retired (goinkyo) daimyo of Mito, who is one of Tokugawa Ieyasu's grandsons. In the drama he wanders around Ibaraki disguised as Mitsuemon, a retired crêpe merchant from Echigo, with two samurai retainers, Sasaki Sukesaburou (Suke-san) and Atsumi Kakunoshin (Kaku-san), helping the oppressed.

Other regular characters include the food-loving commoner Hachibei, reformed thieves Kazaguruma no Yashichi and his wife Kasumi no Oshin, and ninjas Tsuge no Tobizaru and Kagerou Ogin of the Iga School.