Saiga is the Leader of Yami, The One Shadow, Nine Fists, the Master of Kajima Satomi, and the father of Miu Furinji.
It is heavily hinted that he was the killer of Shizuha Fūrinji , Miu's mother. James Shiba, Takeda's boxing Master, also referred to him as the person he had lost to in a fight (and subsequently lost his right eye and injured his left leg) though James also said that he let his guard down. His organization is directed towards promoting the killing martial arts, which is what they believe to be the true fighting arts. This puts them in opposition to Ryōzanpaku. After Shou's death, he chooses his disciple to lead YOMI. Akisame said that he was his best friend in Battle 78. He has also taught his disciple, Kajima Satomi, that the key to winning lies in the 'heart', which is also one of the Elder's lines.