Sōji Okita captains the Shinsengumi's first unit and stands as their most formidable swordsman, his exceptional skill honed through training at the Shieikan dojo under Kondō Isami alongside Hijikata Toshizō. His appearance features chestnut brown hair usually in a topknot, emerald green eyes, and a height of 176–178 cm. He initially wears a distinctive red, gray, and orange haori paired with green hakama and white kyahan leg wrappings, later adopting a blue haori with a black-and-white headband while on duty. As his health fails, he appears primarily in a white sleeping robe. Following a haircut during later events, he shifts to a Western-style outfit in similar color tones. Orphaned at seven, he was raised by his elder sister before entering the Shieikan dojo at nine. There, severe bullying by older students fostered deep emotional detachment and a conviction of abandonment. Kondō Isami's intervention offered protection and mentorship, forging Okita's singular, intense loyalty to him. This trauma shaped his withdrawn nature and lack of self-worth, driving him to seek validation exclusively through his usefulness as Kondō's warrior. His personality merges a charming, sarcastic exterior with underlying combat ruthlessness. He frequently teases other Shinsengumi members, especially Hijikata, masking deeper complexities. Though quick to issue death threats—notably to Chizuru Yukimura upon her arrival as a perceived witness—these often carry teasing ambiguity. Despite his abrasive demeanor, he shows protectiveness, shielding Chizuru during the Ikedaya incident and later from Itō's followers. His moral compass remains ambiguous; he views killing as a practical tool to achieve objectives benefiting Kondō or the Shinsengumi, a perspective solidified in Kyoto's turbulent environment. Diagnosed with tuberculosis after collapsing at Ikedaya, his physical decline forces prolonged bed rest. Desperate to remain combat-effective and avenge Kondō after Sanjo Ohashi, he consumes the Ochimizu elixir, transforming into a Rasetsu (Fury). This grants enhanced strength and regeneration but accelerates his deterioration. In his final act, he single-handedly eliminates assassins targeting Hijikata while in Rasetsu form, expending his remaining life force until his body disintegrates into dust, leaving only his sword. His character development reveals evolving relationships. His bond with Chizuru shifts from detached duty to genuine care, influenced by her treating him as an equal rather than a weapon. He shares a complex, rivalry-tinged dynamic with Hijikata rooted in jealousy over Kondō's attention, yet acknowledges Hijikata's leadership after Kondō's death. His rapport with Saitō Hajime reflects mutual respect and silent understanding. The prequel storyline uncovers earlier struggles: a volatile youth consumed by jealousy over others' combat experience, leading to reckless killings to prove his worth to Kondō, highlighting his fractured sense of purpose and gradual, incomplete emotional maturation.