He interrogated Kodaiyu and compiled "Hokusa Bunryaku" (A Brief Report on the Northern District [currently published by Iwanami bunko]) in 1794, and presented it to the Shogun.
のちに光太夫を訪ね詳しい話を聞き取り、『北槎聞略』(寛政6年・1794年、現在は岩波文庫)を編み将軍に献上した。