Okita's First Corps was constantly tasked with important missions and, although the Shinsengumi was filled with expert swordsmen, often had the most number of kills, and was involved in the assassinations of Kamo SERIZAWA and Hikojiro UCHIYAMA in October, 1863.
沖田の一番隊は常に重要な任務をこなし、剣豪ひしめく新選組の中でも一、二を争う程多くの人を斬ったと言われ、この時期では9月の芹沢鴨暗殺、内山彦次郎暗殺など手がけた。