He developed a cannon called 'Yasuke cannon' and moved from place to place to fight, such as Toba Fushimi and Aizu, leading a new-style musket unit in the Boshin War.
「弥助砲」と呼ばれる大砲を開発するなど、戊辰戦争では新式銃隊を率いて、鳥羽伏見や会津などの各地を転戦。