Mito Kōmon (水戸黄門) is a Japanese jidaigeki or period drama that was on prime-time television from 1969 to 2011, making it the longest-running jidaigeki in Japanese television history. The title character is the historic Tokugawa Mitsukuni, former vice-shōgun and retired second daimyō of the Mito Domain. In the guise of Mitsuemon, a retired crepe merchant from Echigo, he roams Japan with two samurai retainers, fun-loving Sasaki Sukesaburō (Suke-san) and studious Atsumi Kakunoshin (Kaku-san). An episode typically starts with some injustice perpetrated by a corrupt official, a wealthy merchant or a gangster. The travelers arrive incognito, discover the injustice and quietly investigate it. The episode concludes with a brawl in which the unarmed, disguised protagonists defeat a crowd of samurai and gangsters, culminating in the presentation of the inrō that reveals the hero's identity. Afterwards, the hero passes judgement on the villains, sets things straight with comments and encouragement, and then continues with his journey.

Eijirō Tōno was a Japanese actor who, in a career lasting more than 50 years, appeared in over 400 television shows, nearly 250 films and numerous stage productions. He is best known in the West for his roles in films by Akira Kurosawa, such as Seven Samurai (1954) and Yojimbo (1961), and films by Yasujirō Ozu, such as Tokyo Story (1953) and An Autumn Afternoon (1962). He also appeared in Kill! by Kihachi Okamoto and Tora! Tora! Tora!, a depiction of the Japanese attack on Pearl Harbor. His final film was Juzo Itami's A-ge-man in 1990. Tōno also starred as the title character in the long-running television jidaigeki series Mito Kōmon from 1969 to 1983. In the early years of his career he acted under the name of Katsuji Honjo (本庄克二).