However, Kusaka told the plan to Hanpeita TAKECHI of the Tosa clan, who made it known to the head of the Tosa clan Yodo YAMAUCHI, and from him the news reached the head of the Choshu clan Sadahiro MORI, who stopped them from carrying it out recklessly, and ordered them to confine themselves at home.
しかし久坂が土佐の武市半平太に話したことから、これが土佐藩主山内容堂を通して長州藩主毛利定広に伝わり、無謀であると制止され実行に到らず、櫻田邸内に謹慎を命ぜられる。