The first kanji in Hidan's name (飛) stands for hisha, the rook in shōgi. Similarly the first kanji in his partner's name means "bishop".
Before his début in the manga, a character with no clear similarities to Hidan appears during Akatsuki meetings. It is unknown if this is one of Kakuzu's previous partners or simply an early design for Hidan.
According to the databook(s): Hidan is the only member of Nagato's Akatsuki to have never met Naruto Uzumaki. However, in the anime of Tsunade's Infinite Tsukuyomi dream, Naruto encounters Hidan.
Hidan's hobby is "Jashinistic" activities.
Hidan's favourite food is spare ribs. His least favourite are any kind of vegetable or devotion cuisine.
Hidan's desired opponents are heretics.
Hidan's favourite words are "massacre" (殺戮, satsuriku) and "Jashinism" ("ジャシン教", "Jashin-kyō").