The war with Akatsuki had not ended well. In the end, the constant battles that rampaged across the Elemental Nations started to take a heavy toll. Many of the Hidden Villages were out right destroy, including the Hidden Mist and Cloud. Finally, everything got down to Naruto, and the rest of the Konoha Eleven facing off against the revived Akatsuki. The rest of the shinobi were busy taking care of Akastuki's army of Zetsus. The fight was long and both side were taking heavy damage. The fight was made all the more complicated by the arrival of Sasuke and his crew. Finally the battle had pushed the Akatsuki back to their main fortress, the place where the Demon containment statue was held. However, things took a turn, when Orochimaru reared his head once more, taking over Sasuke's body at the height of the battle. It was only thanks to Naruto's latest and greatest Rasengan that he was finally able put Orochimaru, and Sasuke, down for good.
Eventually, Naruto found himself locked in combat Madara atop the Demon statue, both combatants dealing jutsu strong enough to make the earth tremble. But what came next was the move that changed everything. Madara channeled the power of the other eight demons (Killer Bee having been captured just prior to the final battle) and attempted to use his ultimate jutsu. At that moment, Naruto also attempted his ultimate technique. He combined the Rasengan composed of Demon Chakra, with the Rasengan formed of Elemental Chakra. When the two attacks struck each other, it was like all of reality rippled. Just when it seemed all hope was lost, Naruto pushed his jutsu through and struck Madara with all his power. The attack killed Madara, ending the war, and allowing peace to rein.
Only it didn't. Madara's power backlashed, destroying the containment statue. That same backlash contained some of Naruto's own demon chakra with it, which mixed with the other demonic chakra. This mix, combined with the destruction of the statue, caused a massive explosion. The demonic explosion was great and terrible. It killed everyone, on both sides. Konoha and its allies, the Akatsuki, everyone. But that was not all it did. With no bodies to return too, the demonic chakra immediately tried to retreat back to it's home: Hell. That much chakra all going back to hell at once, tore open a portal in space and time. The portal was so great, that it drew everything around it into it. Including the souls of the recently killed combatants. This is where we find Naruto now, about to be pulled into Hell.
Naruto couldn't believe his rotten luck. This was the fight that was supposed to end the war dammit! Naruto looked down at his body, which was glowing an ethereal blue, and then down at his real body, which rapidly disintegrated in the vacuum that he found himself in. Naruto tried with all his might to fight against the current, seeing the souls of many of his friends and in some cases, his enemies, doing the same. But like them, he found himself draw to it. The portal itself was terrifying, the sounds of tortured screams, and the smell of brimstone billowed forth in waves.
Just as Naruto was about to be drawn in, something happened. A white light surrounded him, comforting him. Then all at once, he vanished.
When Naruto came too, he was in a solid white room. The only other thing in said room was a woman of unnatural beauty. Naruto's personality drew to the forefront, and he said the first thing that came to mind:
"Hey Lady, do you know where the hell I am? And who are you for that matter? Where are my friends? What happened down there?
The woman giggled. "My you have a lot of questions don't you. To answer your questions: This is purgatory, the realm between Heaven and Hell. I am Kami." Naruto's eyes widened at that. He had just mouthed off to an all powerful deity! He quickly fell to his knees. The woman just smiled at him before continuing "There is no need for that Naruto. You of all people, have my deepest respect. As for your friends and what happened" here she frowned "that's why I called you here. Please stand" Naruto stood quickly.
"Naruto, when that statue was destroyed, I'm afraid that everyone it killed has been drawn into hell." "WHAT!" Naruto exclaimed "Now hold on. This is where you come in" Naruto stopped freaking out, listening with more attention then he had ever shown in life. "I have a choice for you Naruto, please think about it carefully." Naruto nodded "You can either go down into hell, by yourself, battling the forces of the damned to try and save your friends. Or you can stay here in paradise, getting everything you rightfully deserve." Kami wasn't at all surprised by how quickly the boy answered.
"I'll go. Paradise is nothing without my precious people!" Naruto said, with a fire in his eye.
Kami nodded. "Very well Naruto. But do not think I would send you in completely unarmed." From the blinding light, Kami drew forth a strange looking weapon. It looked like a normal Ninjato at first, with the exception of it being a heavenly white. But at the hilt, a chain was connected, which ended in a wicked looking Kama blade. "This will be one of two of your main weapons when traversing hell. The blade can channel unholy chakra, though it can channel my own holy chakra, if the need arises, to strengthen your attacks." Then she drew forth a glowing medallion, the Uzumaki symbol emblazoned in the center. " This amulet will channel holy chakra for long ranged attacks. I will grant you the knowledge of how to use these properly. And lastly" with a wave of her hand, Naruto's old cloths transformed into a set of solid white-silver armor (it looks like the Altair's armor from AC2) "this armor will help keep you safe. I will also be sending you a guide along the way. She won't be able to help you in combat, but she will provide information and guidance along your path."
Naruto nodded grimly, preparing himself for what was likely to be his greatest challenge. "How do I get to hell?" He asked. "And how do I rescue my friends?" That part concerned him most of all.
"Wait Naruto, patience is a virtue. That's where the amulet comes in. At times, it may seem necessary to send a soul to me. It could be one of your friends, or just a lost soul you feel warrants redemption. When that happens, hold this amulet out and it will cleanse them of their sins and send them to me." Then her face turned grim "On the other hand, if you feel the soul in question has not been punished enough, stab them with your Ninjato, and it will smite them with my fury. That is all Naruto, are you ready to begin your journey?" She asked, genuinely worried for the boys well being.
Naruto nodded. Sure he was frighted, but for his friends, he would literally take on hell itself. "I am Kami-sama."
Kami nodded and waved her hand again. This time a shimmering portal opened up, revealing the gates of hell. She then turned to Naruto and spoke in a serious voice "A word of caution young Naruto. Hell is a strange and cruel place, and it does not give up the souls it takes so easily. And those of exceptionally black hearts and strong wills can even find themselves thriving in hell. You may face a foe you faced in life, more powerful in hell then they ever were before. Hell is also a place of corruption. It can turn any gentle soul into an abomination. All I am saying is, be very careful. This place may try to turn you against yourself, or others against you for that matter" Naruto nodded, his face set in a mask of determination.
"Go forth Naruto, in my name. Save your friends, and smite all who dare oppose your quest." Kami spoke in a regal voice.
Naruto took a deep breath, gripped his Ninjato tight, and stepped through the portal into Hell.