Hidan hails from the Yugakure where he lived during war, soon he had a deep hatred. Hidan belongs to a cult-like faith known as Jashin , after he lived through hatred in his life, it's a religion that worships 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. The amulet around his neck is a symbol of Jashin and he uses it to pray to his god before battling, requesting a good kill, or (when he is not allowed to) for forgiveness. After a fight, should he have time, Hidan performs a thirty-minute ritual consisting of lying within a Jashin symbol inscribed on the ground with a pike impaled through his chest. Hidan claims to be very devout to his faith, refusing to battle Yugito Nii without praying, and often claiming to be bringing his god's judgment down on his opponents.
Hidan is one of the most foul-mouthed, disrespectful characters in the series; he frequently swears and curses at allies and opponents alike. He rarely uses honorifics when speaking, and even then, usually as a form of sarcasm. He is the only member of Akatsuki who does not respect their leader, Pain, and openly declares his willingness to kill him around others. The only respect he ever seems to give is to his god, and even then, he is quite willing to use his name as an insult. He openly holds his partner, Kakuzu, in contempt for his habit of blasphemy, love of money, and frequent ridicule of his religion and battle style. Despite this, whenever Hidan is in the mood to kill, the two work together flawlessly in battle.
He has absolutely no moral restraints regarding who he kills. He considers slaughter a religious calling, and often takes considerable pleasure in making his opponents' deaths as painful as possible. Given the requirements of his voodoo-like curse ritual, he is quite willing to inflict pain and injuries on himself, and openly relishes the shared pain between him and the cursed victim.
However, his immortality has made him very arrogant, and he frequently engages opponents with no regard for strategy, save to acquire some of their blood. Although ridiculed for his stupidity by Kakuzu and Shikamaru alike, and being obviously inferior in tactical genius to either of them, he is able to analyze the nature and limits of Shikamaru's Shadow Imitation Technique and conduct battle accordingly, though he retains his arrogant attitude even under these circumstances. He doesn't particularly like it when Kakuzu assists in his battles, and only calls for his help when he decides he needs it. Kakuzu tends to return the favor by coming in "late" and letting Hidan "die" as punishment for his arrogance.
Hunt for the Two-Tails
Hidan and Kakuzu are first revealed after cornering Yugito Nii, host of the Two-Tailed Demon Cat, in the sewers of Kumogakure. Intially, Hidan arrogantly offers Yugito the option of surrender, claiming his faith does not allow him to fight an opponent only to leave them half-dead (for the capture of her bijuu). However, even when Yugito refuses his offer and transforms herself into the demon cat, the Akatsuki duo manages to defeat her, thus allowing Zetsu to take her off their hands. After Hidan completes his ritual, the duo continues to the Land of Fire.
Assault of The Temple of Fire
Upon arrival in the Land of Fire, Hidan begrudgingly joins Kakuzu in attacking a temple so that they can collect the bounty on the head monk, Chiriku. The monk and his numerous subordinates are defeated and slaughtered, and Hidan repeats his lengthy ritual. Afterwards, Hidan travels with Kakuzu to take the monk's body to the nearest bounty station.
Bounty Station Ambush
Reaching the bounty station, Hidan opts to stay outside, not liking the fact the station is hidden inside a lavatory that smells. While he waits for Kakuzu to collect the money, Hidan is ambushed by Asuma Sarutobi, Izumo Kamizuki, Kotetsu Hagane, and Shikamaru Nara. Despite being immobilized and stabbed in the chest by two large kunai, Hidan surprises the Konoha nin by simply asking who they are.
Kakuzu soon arrives, forcing Hidan's assailants to fall back. Instructing Kakuzu to leave the battle to him, Hidan exchanges blows with Asuma, eventually succeeding in obtaining some blood and initializing his curse. Not realizing what Hidan has done, Asuma charges and falls over in pain when Hidan stabs himself in the leg. As Hidan prepares to kill Asuma, Shikamaru, realizing what's going on, again immobilizes Hidan (with his shadow technique), but has difficulty maintaining his hold on the missing nin. While Hidan is momentarily restrained, Shikamaru analyzes everything Hidan has said and done up to that point, eventually figuring out the weakness of Hidan's technique. With that, Shikamaru manages to force Hidan from the safety of his symbol, temporarily releasing Asuma from Hidan's curse.
After Shikamaru explains Hidan's jutsu and tests the theory, Asuma decapitates Hidan. To the leaf ninjas' horror, Hidan's severed head loudly curses and swears at Asuma for doing so and Kakuzu for not stopping them. Kakuzu casually shrugs this off as Hidan's fault for telling him not to interfere. While Asuma and the others stand shocked by Hidan's survival, Kakuzu reattaches Hidan's head to his body. As Kakuzu deals with Izumo and Kotetsu, Hidan re-enters his symbol and, once more, links himself to Asuma. Hidan swings his scythe at Asuma, only for Asuma to duck and the scythe to bury into Hidan's own vital organs. Asuma doubles over with pain, and as Shikamaru rushes to Asuma's aid, Hidan uses the opportunity to stab himself through the heart with his pike, which fatally injures Asuma.
Reinforcements from Konoha arrive as Asuma collapes on the verge of death. Although Hidan expresses interest in getting to kill them as well, the Akatsuki leader calls him and Kakuzu away. Angry and promising to kill the Konoha nin later, Hidan leaves with Kakuzu to a secluded area, where they spend the next week sealing the demon cat and the Three-Tailed Beast. During this time, all of Hidan's previous injuries were healed.
Konoha's Retaliatory Ambush
Once the sealings are over, Hidan and his partner, Kakuzu, head for Konoha, eager to continue their battle. Along the way, the two are again ambushed by Shikamaru, the latter having been waiting for them. Although Kakuzu manages to escape from Shikamaru's shadow, Hidan is left under Shikamaru's control and is forced to fight Kakuzu.
When Kakuzu is apparently killed by Kakashi Hatake, Kakashi prepares to finish Hidan as well, but is repelled by the still living Kakuzu. Freed from Shikamaru's shadow due to its inherent time limit, Hidan charges at Kakashi while Kakuzu fires blasts of elemental attacks at the two. Recognizing the two Akatsuki are too powerful as a pair and need to be separated (and plotting revenge on Hidan for Asuma's death), Shikamaru volunteers to draw the immortal away. Hidan, having been trapped by Shikamaru's technique so many times, is determined not to fall prey to it again and makes sure to avoid the shadows. In doing so, Hidan mocks Shikamaru for fighting in a sneaky and distant manner. While focusing on the shadow attacks, Hidan doesn't notice Shikamaru suddenly appearing close enough to stun him with a punch to the face. As a result, trapped by Shikamaru's shadow, Hidan is lead away by him.
Hidan is led towards an area that is surrounded with wire and exploding tags, which Shikamaru had prepared a few days in advance. However, Hidan has no desire to escape, and he attacks Shikamaru when the shadow jutsu wears off, managing to get some blood in the process. Quickly drawing his symbol and transforming, Hidan seemingly kills Shikamaru. Once Hidan departs, the fallen leaf ninja jumps up, still alive, and tries to decapitate Hidan from behind, failing to make a cut deep enough. Surprised that Shikamaru is alive, Hidan learns he has been tricked into consuming Kakuzu's blood, so he, in effect, destroyed one of Kakuzu's hearts.
As he tries to kill Shikamaru in retaliation, Hidan is again stopped by Shikamaru's shadow. With Hidan restrained, Shikamaru covers Hidan with the surrounding exploding tags, tying Hidan to the spot. With Hidan unable to move, Shikamaru activates a preprepared mark to cause the ground beneath Hidan to break away. Finally, having a chance to avenge Asuma's death, Shikamaru lights a cigarette and tosses it at Hidan, causing the exploding tags to detonate. As Hidan's remains fall into the pit below, his detached head promises to kill Shikamaru in any way possible. Hidan says that his god will deliver Shikamaru's judgment. Shikamaru causes the pit to collapse, trapping Hidan (who is still screaming curses and threats to kill him) beneath the rubble.
