It is claimed that Ryoma SAKAMOTO was assassinated three days before, but since Shinsengumi was busy scheming to purge the ITO party, it is said that they did not have time to be involved in the assassination of SAKAMOTO.
この3日前には坂本龍馬が暗殺されているが、新選組はこの日の伊東派粛清の謀議のために坂本暗殺には関わる余裕が無かった、と証言している。