Hajime Saitō is a tall, lean man with a long face, pronounced cheekbones, and piercing narrow yellow eyes. His slicked-back short black hair features four distinct forelock bangs, enhancing his wolf-like appearance, a comparison explicitly noted by figures like Shishio Makoto. During the Bakumatsu, he wore the traditional Shinsengumi uniform and a long ponytail, which he cut off upon joining the Meiji-era police force. As an officer, he typically wears a blue uniform, though live-action adaptations show him in all black with a white shirt and boots. He strictly adheres to the Shinsengumi code "Aku Soku Zan" (Swift Death to Evil), ruthlessly eliminating corruption and despots, often expressing a morbid enjoyment of killing. Despite his cold, arrogant demeanor, his dry, sadistic humor surfaces, like casually attempting to stab Sagara Sanosuke through a carriage roof. Duty supersedes personal feelings, and he demands unwavering professionalism from military and police personnel. Though initially dismissive of domestic life, he is married to Tokio, who prepares his favorite soba, and he expresses annoyance when his marital status conflicts with his fearsome image. He later adopts Mishima Eiji after the boy's family dies. Saitō's defining rivalry is with Himura Kenshin, stemming from their opposing Bakumatsu roles—Saitō as a Shinsengumi captain and Kenshin as an Imperialist assassin. Their encounters often escalate to lethal duels, such as their clash at the Kamiya Dojo, where Saitō tested Kenshin under Meiji government orders. While initially viewing Kenshin as an adversary, he gradually respects Kenshin's commitment to non-lethal methods, ultimately ending their long rivalry after acknowledging Kenshin's transformation from the Hitokiri Battōsai. His relationship with Sanosuke involves mutual resentment alongside unspoken respect, particularly after Sanosuke thwarts Shishio's plans to firebomb Tokyo. A former Shinsengumi captain and Meiji government agent, Saitō ranks among the series' most formidable combatants. He is a master swordsman specializing in Shinsengumi kenjutsu, employing a straightforward, adaptive personal style. His signature move, the Gatotsu, is a refined thrust derived from the historical Shinsengumi's hirazuki technique, noted for unparalleled stabbing power—capable of breaching steel doors even while he is severely wounded. Ambidextrous, he seamlessly switches stances to confuse opponents. Beyond swordsmanship, he excels in hand-to-hand combat, integrating jujutsu, judo, and aikidō maneuvers. His physical strength lets him withstand blows from opponents like Sanosuke and counter with overwhelming force. He is also a perceptive tactician, exploiting weaknesses and using environmental tools like belts or clothing when disarmed. During the Bakumatsu, Saitō served as the Shinsengumi's third squad captain, participating in events like the Ikedaya Affair to prevent Kyoto's burning. Following the pro-shogunate defeat, he used the alias Fujita Gorō and joined the Meiji government as a spy. In the Kyoto Arc, he allies with Kenshin and Sanosuke against Shishio Makoto, killing Usui and ambushing Shishio—though Shishio survives due to a hidden iron headband. Later, during the Jinchū Arc, he aids Kenshin against Yukishiro Enishi's Six Comrades, defeating Yatsume Mumyōi and one of Enishi's guards. He rejects a final duel with Kenshin before transferring to a new post. Five years later, he continues government work. In the Hokkaido Arc, he investigates the Kenkaku Heiki, sustains severe injuries from Itekura Byakuya, and reunites with former Shinsengumi allies like Nagakura Shinpachi to counter this threat. In other media, the OVA *Rurouni Kenshin: Trust & Betrayal* depicts his Bakumatsu activities and interactions with Okita Sōji. The film *Rurouni Kenshin: The Motion Picture* shows him collaborating with Kenshin to protect a foreign minister from rebels led by Takimi Shigure. Live-action films highlight his combat prowess, including arresting Takeda Kanryū and confronting Shishio's forces. The *New Kyoto Arc* films condense or alter some of his manga scenes.