On April 21, 1701, since Naganori ASANO cut at Yoshinaka KIRA inside of the shogun's castle, it was decided to impose Kaieki punishment on Naganori, which means he would be dismissed and his castle called Ako-jo Castle would be confiscated.
元禄14年（1701年）3月14日、浅野長矩が吉良義央に殿中刃傷に及んだため、赤穂城の改易城召し上げが決定された。