Kambei's "right hand man." Kambei and Shichiroji fought in the Great War side by side and thus have become the best of friends. He temporarily leaves behind his successful post-war business, and with it, his "girlfriend", to join Kambei in battle once again.
Unlike the other samurai, Shichiroji uses a kamayari as opposed to a katana that the other samurai use. He has a prosthetic left hand which has a grappling hook capability.
He is often nicknamed Momotaro, from the traditional Japanese tale, as he was found by his girlfriend, Yukino, badly injured after a battle floating down a river inside a capsule reminiscent of a peach.
(Source: Wikipedia)