Seta Sōjirō (
Sōjirō is normally seen smiling, with seemingly no emotion. In actuality, he subconsciously suppresses his emotions, making him difficult to read in combat, as stated by Kenshin. This façade gradually erodes when he realizes how strong of an opponent Kenshin is. He also adheres to the philosophy of "the survival of the fittest" and believes it to be an absolute truth. His dedication to this belief, however, leaves him emotionally vulnerable and naive when another's differing ideology conflicts with his own. When his true emotions surface, he appears to be unnerved, infuriated, and almost insane. This is a direct result of spending over a decade suppressing his feelings due to the trauma and abuse he suffered as a child.
As a child, he was a kind, calm patient child who often smiled to avoid the abuse his father's family often caused due to him being a product of infidelity from his father and a prostitute, something that brought great shame upon his father's family. He would obediently follow their orders, no matter how ridiculous and labor-intensive, and endured much of their abuse and bullying, which was unjustified and cruel. He only broke this smile upon first meeting Shishio, whom he was scared of. However, he quickly grew attached to him, and Shishio taught him that the strong lives and the weak dies. When his family threatened to kill him to get the reward money and the fact they wanted to get rid of him for good, a part of him snapped, and he had no choice but to kill them before they killed him, when he killed his older half brother, the other members of the family were horrified and he ended up slaughtering them all. While on the inside he was crying because of what his family wanted to do to him and how they hated him for something that wasn't his fault, he outwardly smiled to hide the pain and grief because, despite their abuse and apparent lack of love for him, he still thought of them as his family. This abuse and trauma led him to become emotionless and always hold a smile, though he was broken on the inside.
Eventually, after Kenshin fought him, it began to clash with his ideas of the weak and strong that Shishio implanted in him. This is because, to him, Kenshin was weak since he couldn't kill his opponents and often defended those weaker than him. In addition, this caused him to doubt the very philosophy that allowed him to live for so long and keep hold of what little sanity he had. A part of him also wondered why someone like Kenshin didn't save him and teach him better. Despite having had to kill multiple people during his life on orders of Shishio, it is hinted a part of him never wanted to kill people, and he had only done so to keep with the philosophy of strong and weak. Eventually, Kenshin teaches him that he needs to develop his own life philosophy through his own experiences rather than blindly follow Shishio. After the Kyoto Arc, he appears to have calmed down somewhat and gone back to his happy-go-lucky self while going on a ten-year journey to find his philosophy of life.
During his time under Shishio's teaching and service, Sōjirō seems to regard him as a combination of master and foster father.
Sōjirō was an illegitimate son of a rice businessman and was left in the care of his much older half-brother. It's unknown what happened to his mother. As a child, Sōjirō was abused and beaten by his family as he was a constant reminder of his father's infidelity and the shame he brought upon his family. Sōjirō's father was never punished or shamed for it personally by his wife or adult children, and Sōjirō was an easy target for their anger since he was a defenseless child, and he would smile instead of cry to make them stop temporarily. One night, he ran into Shishio Makoto, who sliced a government official in half. Instead of killing Sōjirō, Shishio took shelter in a shed, and Sōjirō would bring him food and bandages. He gave Sōjirō a wakizashi to protect himself by killing his family, but he thought being killed by a sword would hurt too much, so he hid it under the porch. When his "family" found out Sōjirō was harboring a wanted criminal, they planned to kill the boy and turn Shishio in, causing Sōjirō to snap and he had no choice but to kill his abusers before they could kill him. Sōjirō ended up slaughtering the five adults with great speed and strength, the result of believing what Shishio told him; "The strong live and the weak die." Afterward, when he stood in the rain, he seemed to be smiling about it, but he was crying and was angry with his family. He decided to go with Shishio.
In his first appearance, Sōjirō killed Okubo Toshimichi under Shishio's order; his abilities made his presence unnoted. After Kenshin defeated Senkaku, Sōjirō engages in a fast duel with him, resulting in a tie. Then, Shishio ordered Sōjirō to bring him The Ten Swords from the East side of Japan.
Sōjirō was the last member of Juppontagana that Kenshin must defeat before facing Shishio. He used Shukuchi's less potent forms to move fast enough to hit Kenshin, both managing to dodge the Kuzuryusen and slash him in the back using merely the second step behind the true Shukuchi. As the fight dragged on, however, Kenshin made Sōjirō question the reasons that made him fight alongside Shishio, and this made Sōjirō release his true emotions, allowing Kenshin to predict his moves and discover his advantages. Sōjirō got mad and rendered his emotional blankness null; the battle reaches the climax when Sōjirō challenges Kenshin to do the last technique to put an end in the duel, Sōjirō used Shuntensatsu, the combination of the full Shukuchi and his Battojutsu against Kenshin's Amakakeru Ryū no Hirameki. The two attacks were comparable in overall speed, but Kenshin's ōgi was far stronger and instantly broke Sōjirō's sword and left him battered. Sōjirō declared that his loss showed he had been wrong, but Kenshin instead said that the victor isn't right by default, and he must discover his own truth before leaving the room to face Shishio.
Sōjirō discovered the key to Amakakeru Ryū no Hirameki and informed Yumi to tell Shishio. Sōjirō asked for Yumi to return the Wakizashi given to him by Shishio. Then, he left the Juppongatana and became a traveler once Shishio died, intending to travel the next ten years to discover his true self while being on the run as a fugitive. Cho stated his confidence that Sōjirō would never be caught.
- Shukuchi (
縮地Reduced Earth ) Sōjirō moves at such speed that cannot be perceived by the human eye, only showing his footsteps crashing into the floor. This also allows him to run on walls. He is also shown to use reduced forms of the technique, naming them (X) steps below shukuchi. Shukuchi is revealed to be the reason why he could keep up with Okubo and kill him in his carriage. The effect is devastating enough it punches breaches into the tatami floor, however it also damages the footwear of the practitioner using it.
- Shuntensatsu (
瞬 天 殺Blinking Heaven Kill ) This is the only attack Sōjirō named himself. It involves using Batoujutsu combined with the speed of Shukuchi. It is called for its ability to instantly kill its target victim, a process that wouldn't even be painful due to the speed with which the target is dispatched. Sōjirō was supremely confident in its ability to demolish Kenshin. Still, by combining his Shinsoku with the ōgi used to defeat Aoshi earlier on (Amakakeru Ryu no Hirameki), Kenshin won the battle.
- Shishio Makoto - Mentor and father figure: Sōjirō first met him as a child when Shishio suffered burns and Sōjirō merely smiled when asked if he was not afraid of death. Once Shisho realized that Sōjirō was abused by his family he gave him a wakizashi as payment for the food and bandages he had received, which Sōjirō used to kill his family once they tried to kill him. Sōjirō learned swordsmanship from Shishio and regarded him as a father.
- Komagata Yumi - Sister figure: Sōjirō became close to Yumi who, like his mother, was a prostitute. She showed much concern for his wellbeing, even after he resolved to leave their faction. He had high regard for her.
- Himura Kenshin - An enemy to Sōjirō, since the latter was Shishio's top henchman and wanted to end Kenshin's life with his own hands. Eventually, after a hard-fought battle, Sōjirō loses to Kenshin in their second battle (after a draw in the first), and his adversary tells him that he must find for himself, the correct path in life, the way he did.
In Live Action film
A 5-minute preview of the film shows that Sōjirō was responsible for the kidnap of Kaoru, under the orders of Shishio.
Like the anime and manga, The Legend Ends trailer shows Sōjirō's breakdown to Kenshin.
Creation and conception
Nobuhiro Watsuki has stated that the character design of Sōjirō is loosely based on Okita Sōji, the captain of the first Squad of the Shinsengumi. The name Seta Sōjirō originates from "Okita Sōjirō," the name Okita had in his early life. The specific personality model is from the Okita in Ryōtarō Shiba's novel Shinsengumi Keppuroku ("Record of Shinsengumi Bloodshed"); in that version Okita "lost an important part in his human heart," making him without emotions and "pretty scary." Watsuki reported that some fans did not like the fact that a character modeled on Okita is a villain; Watsuki argued that since Sōjirō is based on the Shinsengumi Keppuroku Okita, the design "works well" and that Sōjirō is "a strong antagonist." Watsuki felt that Sōjirō was more difficult to draw than Watsuki initially anticipated, and that he only accomplished around one fourth of what he imagined the character would appear in his mind. Watsuki had no design model for Sōjirō; Watsuki envisioned Okita as having bangs (fringes), so to Watsuki it was no surprise that Sōjirō also had bangs. Watsuki gave Sōjirō a "slightly feminized air" so that Sōjirō's smile would "look good" on the character. In Volume 9 Watsuki stated that he wants to properly portray Sōjirō since he is a popular character.
The fact that Sōjirō has no emotions is also based on Shiba's version of Okita Sōji. Watsuki said that this concept became one of the most difficult aspects to reflect in the drawing. Okita died when he was young, but Watsuki decided not to kill Sōjirō in the story in order to atone for the murders he committed, but instead start living on his own instead of having someone make his decisions for him. He hoped to draw him in more of the next chapters but soon thought that would not be possible.