He was born in either 1775 or 1780, in Kami-Hirayanagi village, Tsukuba district, Hitachi province, as Mamiya Tomomune. He studied surveying under Inô Tadataka, and was appointed by the Tokugawa shogunate to explore and survey Ezo (today called Hokkaidô).
In 1808, alongside Matsuda Tenjûrô, he surveyed the island of Sakhalin (Karafuto), on the shogunate's orders. On 1809/7/2, he crossed over to the Siberian mainland alone, and entered the Russian Maritime Provinces, after which he followed the Amur River upstream. In the process of his 15 months of exploration of the region, he was the first Japanese to discover or confirm that Sakhalin is an island, and not attached to the Asian mainland. The straits between the two, known as the Straits of Tartary in English, came to be known as the Mamiya kaikyô (Mamiya Straits) in Japanese.
Mamiya is buried in the Fukagawa neighborhood of Tokyo.
- Plaques on-site at Mamiya's grave, 2-7-8 Hirano, Kôtô-ku, Tokyo.