In his later years, he told the detail of the Omiya Incident to people such as his brother Yasuhei WATANABE and his disciple Tsunenosuke IIDA as he killed Ryoma by the sword 'Dewa daijo Fujiwara Kunimichi ' which was given to him by his father.
晩年、近江屋事件の様子を弟の渡辺安平や弟子の飯田常之助などに語り、父から贈られた刀「出羽大掾藤原国路」で龍馬を斬ったと述べている。