Daikokuya Kōdayū, born in Wakamatsu, Ise Province (Suzuka, Mie, Japan), had been adopted by a merchant, Daikokuya in Shiroko, Ise (also in Suzuka, Mie).

As the captain of the ship, Shinsho-maru, Kōdayū sets sail for Yedo in 1782, but the ship is caught in a storm around Enshū (Western Shizuoka).

Adrift seven months, one man dies.

Just afterwards, the remaining fifteen sailors find and land on the island of Amchitka, the southernmost of the Rat Islands group at the western end of the Aleutian islands chain, where Russians and Aleut people live.

Russian trappers and traders have established settlements on the islands, exploiting the indigenous people, whose population on the island of Amchitka is quickly falling.

According to a later account by Kōdayū, the islanders receive necessities and supplies such as tobacco, ironware, horse- and ox-skins, and cotton in return for hunting otters or seals.

The furs brought by indigenous people are divided into thirds between the Russian Empire, Moscow furrier Vassily Yakovlevich Zhigarev, and Zhigarev's Russian employees.

The castaways are taken care of by Russian employees of Zhigarev and hunt with indigenous people.