Soujirou Seta is a key antagonist in the anime and manga series 'Rurouni Kenshin: Meiji Kenkaku Romantan.' As the right-hand man to Shishio Makoto, Soujirou is known for his calm demeanor, speed, and deadly swordsmanship. Despite his constant smile, he hides a traumatic past that shapes his outlook on life and battle. His confrontations with Kenshin Himura are pivotal, serving as both a formidable foe and a tragic figure influenced by the harshness of the era.