Hidan (飛段, Hidan) was an S-rank missing-nin who defected from Yugakure and joined the Akatsuki. There he was partnered with Kakuzu despite the two's somewhat mutual dislike of each other. He was also the second newest member of Akatsuki at the time of his introduction. Kisame laughingly referred to Hidan and Kakuzu as the "Zombie Combo" (ゾンビコンビ, Zonbi Konbi).
After Yugakure deteriorated from a shinobi village to a tourist site, Hidan became infuriated with how things were turning out. He believed that the shinobi that resided there were meant to kill, and thus slaughtered his neighbours before leaving Yugakure, and joining the cult-like faith known as Jashin, a religion that worshipped a deity of the same name. The primary teaching of this faith appears to be outright slaughter, where anything less than utter destruction is considered a sin. Through experiments with Jashin's secret technique, Hidan was granted with immortality. Eventually, he joined Akatsuki after seeing Kakuzu, a man who he saw as a pioneer in immortality, and he was later partnered with him.