During the Boshin War, sailors of Kanrin-maru, a ship of the Fleet of Enomoto Takeaki in the port of Shimizu, fought soldiers of the new government's forces and the dead bodies of the sailors were abandoned there (it is a famous story that SHIMIZU no Jirocho buried the bodies and gained a reputation for courage) and later during the Meiji period, a stone monument was erected for the war dead in the precincts of Seiken-ji temple in Shimizu; when Yukichi took a trip with his family to Shimizu, he read and got furious about the epitaph signed by Takeaki ENOMOTO on the monument, which said 'Men who served their master died for their master (which means that the servants of the Tokugawa family died for the Tokugawa family).'
戊辰戦争の折に清水港に停泊中の脱走艦隊の1隻である咸臨丸の船員が新政府軍と交戦し徳川方の戦死者が放置された件（清水次郎長が埋葬し男を上げた意味でも有名）で、明治になってから戦死者の慰霊の石碑が清水の清見寺内に立てられるが、福澤は家族旅行で清水に遊びこの石碑の碑文を書いた男が榎本武揚と銘記され、その内容が「食人之食者死人之事（人の食（禄）を食む者は人の事に死す。即ち徳川に仕える者は徳川家のために死すという意味）」を見ると激怒したという。