He was imprisoned together with his brother after the plot to assassinate Akikatsu MANABE, roju (member of shogun's council of elders), was exposed, but participated in the fire attack against the British Legation.
老中・間部詮勝の暗殺計画が露見して兄と共に投獄されるが、1862年にはイギリス公使館の焼き討ちに参加。