Age: 28
Birthday: September 4 (Virgo)
Hair: Dark brown
Eyes: Brown
Height: 184 cm
Weight: 80 kg
Blood type: A

Kondou Isao is the Commander of the Shinsengumi. When not working, he is also the stalker of Shimura Tae, earning him the nickname Gorilla-stalker.

His superior is Matsudaira Katakuriko, a high-ranking government officer under direct control of the Bakufu. Even though the Shinsengumi are loyal to Kondou, he often has to use the Shinsengumi Vice-Commander Hijikata Toushirou to settle them down (with harsh words or use of violence) before conducting a speech.

Kondou is good friends with Hijikata Toushirou and Okita Sougo of the Shinsengumi, and if one of them ever strayed, then the other two would punch him back to where he belongs, as Kondou once told Sougo. Sougo also often remarks that Kondou's nice-guy attitude is also his weakness as he never notices negative points about other people.

In the Mutiny arc, he was described by Itou Kamotarou as honest, pure and unsullied. In the same arc, Hijikata Toushirou described him as the soul of the Shinsengumi, and the rest of them being the sword that protects him. Hijikata also said that everybody joined the Shinsengumi so that they could be with Kondou, and that as long as he was there, the Shinsengumi would not be finished.

When Kondou once asked Shimura Tae whether she would still love her boyfriend if he had a hairy butt. She became the target of his stalking when she replied that she would love her boyfriend just as much, hairy butt and all. Being a stalker of Tae, Kondou is often seen getting beat up or threatened by her, as she highly disapproves of his stalking and affection towards her.

In the Yagyuu arc, Kondou had his mind set on being Shimura Shinpachi's brother-in-law, even going as far as saying Shinpachi was the only one he could entrust the Shinsengumi to, much to Shinpachi's annoyance, answering that he doesn't give a damn about the Shinsengumi.

In his childhood, Kondou Isao was a member of a dojo in Bushuu. There, he would soon meet Okita Sougo and Hijikata Toushirou, recruiting them both into his dojo. Kondou would later on take all the members with him and move from Bushuu to Edo in search for success, becoming what is now the Shinsengumi.

Some characters in the series often call him "gorilla" due to his hirsute nature and although he is angered with this nickname, he sometimes uses the same word to identify himself.

Kondou is loosely based on the historical Kondou Isami, famed for his role as commander of the Shinsengumi during the Bakumatsu period.