Daikokuya Kôdayû was a fisherman from Shiroko, in Ise province, who became perhaps the most prominent Edo period Japanese to spend time in Russia, and to report back to the shogunate about that country.
After the fishing vessel he was captaining floundered in the North Pacific, he was picked up by a Russian ship, and taken, along with at least one of his crewmembers, to St. Petersburg, where they were presented to Catherine the Great.
In 1792, Kôdayû and his crewmember Nagao Isokichi were escorted back to Japan by Russian envoy Adam Laxman, who was hoping that, using the repatriation of castaways as an excuse for entering Japanese ports, he might then be able to negotiate the opening of trade relations. The Russians were stalled at Matsumae, and eventually redirected to Nagasaki, while Daikokuya and Nagao were taken to Edo (Laxman never traveled to Nagasaki, but simply returned home). Officially, leaving Japan (or, more precisely, returning) was punishable by death. However, because of Daikokuya's ability to provide the shogunate with valuable information about Russia, he was instead allowed to live, and was interrogated by Katsuragawa Hoshû, a rangaku scholar and personal physician to the shogun. Katsuragawa presented his report, entitled Hokusa bunryaku, to Shogun Tokugawa Ienari in 1794.
- Mitani Hiroshi, David Noble (trans.), Escape from Impasse, International House of Japan (2006), 27.