Mamiya was born in 1775 in Tsukuba District, Hitachi Province, in what is now Tsukubamirai, Ibaraki Prefecture. Later in his life he would become an undercover agent for the Tokugawa shogunate. He is best known for his exploration and mapping of Sakhalin (known to the Japanese as 樺太, Karafuto), which resulted in his discovery that Sakhalin was indeed an island and not connected to the Asian continent, although this had already been discovered by Jean-François de La Pérouse in 1787, who charted most of the Strait of Tartary.
In 1785 Japanese explorers reached almost to the Strait of Tartary on the west, Cape Patience on the east and Urup in the Kurils. In 1808 Mamiya sailed up the east coast and Matsuda Denjuro up the west coast. From near Cape Patience Mamiya crossed the mountains to join Matsuda. The next year Mamiya sailed into the mouth of the Amur River and reached a Chinese trading post. In 1852 Mamiya's maps were published in Europe by Philipp Franz von Siebold.
In popular culture
Mamiya is portrayed as one of the two main villains in the manga series Shin Kozure Okami (New Lone Wolf and Cub). In this version, he is the chief henchman of Matsudaira Nobutsuna (and his natural son) and a master of disguise who assumes different identities after murdering the original persons. He is also possibly even more ruthless that Matsudaira, subverting various ninja groups for his own use and using opium as a means of ensnaring and controlling various people, including the Shogun. While Mamiya's historical explorations are mentioned, in this version they have been for a more malign purpose than mere exploration.
- 間宮林蔵の子孫が一堂に 茨城県・伊奈町. 47 News (in Japanese). October 25, 2003. Retrieved April 19, 2011.
- Derek Hayes, Historical Atlas of the North Pacific, 2001