Masked Blade (1983)

Original title: 長七郎江戸日記

Choshichiro Nagayori Matsudaira is the son of Tadanaga Tokugawa, which makes him a nephew of the Shogun. Tadanaga died as a result of an alleged plot to overthrow his elder brother, the third shogun Tokugawa Iemitsu. Because of Choshichiro’s complicated background, he lives among the commoners in the shogunal capital city of Edo, punishing the evil when he sees wrongdoings and injustice.