Gen Shogo (Tanmei Jiro) is described as a man with eyes resembling bells, arms like iron staffs, and a leopard tattoo on his chest. Although he always wears a smile on his face, he has a "murderous" look in his eyes. His nickname "Tanmei Jiro" or "Short-lived Second Brother" does not imply that he is short-lived; it actually means that his enemies are short-lived when they meet him and his smile.
Gen Shogo is one of three brothers. The brothers earn a living by fishing and are very skillful in swimming and underwater combat.