Background
Tokunai Mogami was born in 1755. He was the son of a farm family of the village of Tateoka in the province of Dewa.
最上 徳内
Tokunai Mogami was born in 1755. He was the son of a farm family of the village of Tateoka in the province of Dewa.
He became a servant in the household of Yamada Tonan, a physician in the shogunate. Later he entered the private school in Edo operated by the geographer and economist Honda Toshiaki, studying astronomy, geography, surveying, and navigation under him. In 1785, when Honda Toshiaki was incapacitated by illness, he took Honda’s place in participating, along with Aoshima Toshizo, in a party sent out by the shogunate to explore Ezochi, as Hokkaido was called at that time, and the Chishima (Kurile) Islands. The party succeeded in carrying out a survey of the southern Kuriles.
In 1789, when the Ainu of Kunashiri rose up in revolt, Mogami acted as guide to the investigation party sent out by the shogunate. In recognition of his services, he was advanced from the post offushin-yaku shitayaku, a rather lowly position in the shogunate, to that offushin-yaku. In 1791 he conducted another exploration of the southern Kuriles, and the following year of Karafuto (Sakhalin).
In 1798 he and Kondo Juzo (Morishige) sailed to the island of Etorofu. In 1807 he became a shir obeyaku-nami, or supernumerary invesitgation official in the Hakodate-bugyo, the shogunate administrative office in Ezochi. When the Russian envoy Laxman escorted to Matsumae the Japanese seaman Daikokuya Kodayu, who had been shipwrecked in Siberia, Mogami was assigned to receive him. In 1826, when the German doctor von Siebold, who was attached to the Dutch trading office in Nagasaki, visited Edo, Mogami lent him a copy of the survey map of Ezochi, helped him to compile a glossary of Ainu words, and presented him widi botanical specimens from Ezochi. Siebold, in his work on Japan entitled Nippon, duly records the debt that he owes to Mogami.
He died in the ninth month of 1836.