He questioned the human anatomical chart created based on the Inyo-gogyo-setsu (the China-origin doctrine that everything in the universe is made of five basic elements, and has two opposite aspects) when he dissected an otter; therefore, he dissected and observed the body of an executed criminal in March 1754 with permission of the Kyoto shoshidai (governor general).
カワウソの解剖から陰陽五行説に基づく人体の内景に疑問を抱き、1754年(宝暦４年)閏２月、京都所司代の許可を得て死刑囚の解剖、観察を行う。