Kiri-sute gomen (? or ?, "authorization to cut and leave [the body of the victim]") is an old Japanese expression dating back to the feudal era right to strike (right of samurai to kill commoners for perceived affronts). Samurai had the right to strike with sword at anyone of a lower class who compromised their honour.
Because the right was defined as a part of self defence, the strike had to follow immediately after the offence, meaning that the striker could not attack someone for a past grievance. Also, due to the right being self-defence, it was not permissible to deliver a further coup de grâce.
Because of the somewhat arbitrary nature of this right, anyone who was at the receiving end had the right to defend themselves by wakizashi (short sword). This situation was most common in the case of a higher samurai exercising the right against a lower ranked samurai as samurai would always carry wakizashi.