Kaikyō no fūunji

Araki Mataemon was a very strong warrior, and his feud against the samurai Kawai Matagorō is one of the most famous in Japan. Matagoro killed Gendayu, the little brother of Mataemon's brother in law, Watanabe Kazuma. Becoming a murderer out of jealousy for a childhood friend, Matagoro fled in another domain, using friends of his father and his lineage linked to Tokugawa Ieyasu. It was somehow a complicated matter, as it seems at that time, a law from Toyotomi Hideyoshi allowed a little brother taking revenge for his elder brother, but not the reverse. After some years, the lord of Kazuma and Mataemon found a way, and they were allowed to take revenge for the murder. They fought and killed Matagoro and just one other samurai who was helping the culprit. It seems at that time, Kazuma was Mataemon's only assistant.

An important silent film survives, Kumahiko Nishina's Umon torimonocho rokuban tegara jinenji kidan (The Samurai Detective, aka The Detective Records of Umon, aka Detective Umon Diary: Exploit Number Six, 1930). Umon on his shining white horse stops a conspiracy against the Shogun. Umon was played by Kanjuro Arashi in this early film, & long after in the post-Occupation jidaigeki revival he reprised the role in Kajiro Yamamoto's Muttsuri Umon torimonocho (1955), helping to launch the renewed interest in such films.