Ito planned to assassinate Kondo (there has been a theory however that Ito never thought about assassinating Kondo), but instead, on December 13 of the same year, Kondo made Ito drunk and ordered Kuwajiro OISHI to assassinate Ito on his way home.
伊東は近藤を暗殺しようとたくらむが（伊東には暗殺しようなどという気持ちはなかったという説もあり）、同年11月18日、近藤は伊東を酔わせ、帰り際に大石鍬次郎等に暗殺させた。