-Chapter 1-
This world's quite interesting. Naruto had visited a world where vampire and werewolf lived alongside human. He also had visited a world where youkai was real. There was also a world where angel and devil existed. Also, there's a world where gods/goddesses were real. But here, in this world, every weird beings existed. It's like a mix of all worlds. Quite interesting, Naruto liked it.
According to Great Red, at first this world consisted only of monsters, dragons, and beasts. No human. No gods/goddesses. No angel. No devil. No youkai. No vampire. Nothing but a bunch of beings who lived by the rule of survival to the fittest existed in the world that was no different to a wasteland.
Great Red itself was born from the blood of many dragons who dreamed to be the strongest and become the ruler of the world. Those dreams reacted strongly with each other, causing the blood of the death dragon to want to fulfill it. Such thing, by the influent of the world that needed a king, made it possible for Great Red to exist. For hundreds of years Great Red lived as the emperor of all dragons, thus bringing the dragon race into the top hierarchy of the world.
That lasted not long, however. A woman whose strength was above even Great Red suddenly appeared out of nowhere. Great Red was threatened. He had been ruling those dragons for hundreds of years; Great Red didn't want to be ruled by anyone. So, he challenged that woman, wanting to prove that he's the strongest.
Though, that woman—of which later introduced herself as Mavis Vermillion—refused to fight him. "I hate fighting without reason and that you remind me of my deceased teacher," she reasoned. Being a proud Dragon Emperor he was, Great Red did not take rejection kindly. So, he went his way and attacked Mavis.
They fought for weeks, shattering the already wasteland into something akin to hell hole.
Great Red admitted defeat. He was ready to be killed. However, Mavis didn't bother with the Dragon Emperor's sentiment that the strongest should rule the world. Instead, she asked him to tell her stories. Long story short, Mavis ended up separating the world into two: Upper World and Under World. In Upper World lived beings with sane mind, while the ones mindless were to live in Under World. Separating the two was a void, from within it born a being of infinity at a later time, for even the void was being influenced by the consciousness of the world.
A couple of hundred years passed. Mavis had no talking partner other than Great Red. So she sought to reach the world's consciousness. Like in every world, the world itself had consciousness. Earthland itself had nature kind of consciousness. This world's, however, was a divine energy clouded by nature. Mavis, being Mavis she was, tried to connect herself with that divine energy. Hence, the world's acknowledged her as its god. Though, in return, it took a part of her power and used it to heal itself—thus explained why Naruto felt Mavis' presence showering the world. Then, the world became a better place, both the Upper World and the Under World, the consciousness of the world used Mavis' power to heal both.
Though, in order to truly fit the title of "God", the consciousness of the world decided Mavis should have follower. So, that day, thing called "evolution" took effect. Except of Dragons who're already sapiens beings, beast and monster by sacrificing part of their power evolved into more sapiens. After eon, there were far less beast in existence, and there's no longer monster. At that time, human—the most sapiens out of all beings—started their very first civilization.
By that time, Mavis lost quite sums of her prowess that Great Red thought he finally had the chance to defeat the woman. Though, much to Naruto's surprise, Great Red did not challenge the woman. He said, "I prefer to watch what you intent to do." So, the day that human worshipped god had finally come. The consciousness of the world had done its job, so it fell into slumber.
However, it was not a complete success of fulfilling the concept of god. By granting the world its power, the consciousness of the world also spread away its divinity. Human wished for more gods/goddess, one was not enough to satisfy their greed. Thus, to fulfill those wishes, that divinity dispersed into any being of resemblance to the wish of the human. As a result, many, many more gods/goddess came into existence. Thus, pantheon/mythology came into existence.
That's not all. The Evolution also brought forth to many, many strange beings. Vampire, Werewolf, Youkai, are a part of those. However, no one was as dangerous as Trihexa. That being was the very personification of a beast, a truly dangerous one. Luckily enough, Trihexa was born in Under World, so it did not threaten the Upper World. However, due to resentment toward Dragons who once looked down on beast, Trihexa sought the extinction of dragon race.
Mavis and Gread Red naturally couldn't let it happened. So, Mavis created a small dimension at far corner of the void (of which later known as Dimensional Gap) and asked Great Red to hold on the lord of the beast. That small dimensioned was named "The End of the World". Mavis sealed that beast inside it. Killing it was not a good idea, Trihexa was at the same level as Great Red and Mavis—who had lost a considerable of power. If those three chose to fight, the world would no doubt return to its former self, a hell-hole of wasteland, with no one alive but the three of them.
"Please, kick that stupid-overgrown lizard out of my home."
Naruto thought suddenly came to a halt. That voice which interrupted his thought belonged to a petite black haired girl, of the same high as his beloved Mavis. Ophis Ouroboros the Shape-shifter, the Dragon of Infinity who took form of a little girl cladded in gothic-lolita cloth with white legging covering her white smooth legs. Naruto had lectured her a while ago when she presented herself in an inappropriate style of clothing; the way she dressed now suited her better. Such Ophis, was now staring blankly into his Eternal Mangekyou Sharingan, waiting a "okay" to erupt out of his mouth.
"My wife is the one who asked him to live there," said Naruto with eyes deadpanning. "There's no way I will force him out. Besides, he is stronger than you; he is better at keeping the gap safe than you ever can."
"Then, I can become your wife, and you will give me your chakra, and then I will be stronger than Stupid Red, thus making me a better gap keeper." As if proving her words, Ophis shape shifted into Mavis—an expressionless Mavis, to be precise.
Naruto stared at "Mavis". "Mavis" stared back at him. Naruto sighed. "Mavis" tilted her head to the left.
"So, will you now kick out that Stupid Red?"
…Dozen Years Later, Kuoh Town…
Issei was pervert, a proud pervert. He liked to read and watch porn. He liked to peek inside girl's cloth, curious to see what they're hiding from him. Of course he, too, played with his hand on a couple of time, using a movie that is hated by most "normal" people. Though, shamelessly, those "normal" people did that thing which the people inside the hated movie did. They're hypocrite, beyond disgusting. All human are pervert at heart. That's a matter of fact. Issei was one of the honest one, he admitted that he's pervert. Which one's better, an honest person or a hypocrite one?
Regardless, Issei did not care. As long as he could enjoy his time, the others' opinions did not matter in the slightest. Though, Issei was not a disgusting pervert. A teacher had taught him a lesson that a proud pervert should follow: "Never ever peek, ogle, or fantasize a married woman; you don't want a friend of yours fantasizing your mother, do you?" Issei followed that rule to his heart content. He was not a son a mother wished for, but he's still a son that would protect his mother at all cost.
Besides, he was a member of Akatsuki—a group consisted of special human with the power of Sacred Gear. He couldn't tarnish the name of the group by being a disgusting pervert. They had saved his life when he was being stupid trying to kiss a truck so that he could reborn in a world full of woman wearing no cloth, with him as the sole male. It was stupid of him, he admitted that, but that stupidity brought a miracle in his life. A young teen named Jeanne helped him, told him that he had a great power, a power to save humanity and to fulfill his perverted wish. That day, he was invited to join them.
Thinking about a group that had recruited him a year ago, Issei remembered something important. So far there's only nine human forming that group, today the "Leader" told him that another one would be recruited, and he would become the final member's partner. Issei hoped the last member would be a female, it was only right for the holder of the awesome Boosted Gear to have a beautiful woman as his partner. Is not that right, Partner?
"One of these days you will die while having a pervert dream, Issei."
Well, if there's a naked woman next to me, I'd not mind it.
"I'm not surprised."
Issei's lips almost cracked into a grin at hearing his partner's, Draig, response. But he held in. He couldn't let people think he's crazy, right? It was enough to be called pervert, being called crazy would clearly annoy him. So, it was better not to be called that.
Not long after, Issei reached school's rooftop. This was a better place for him to observe the beauty of the girls in sport uniform. Though, expectedly, a red haired girl had been waiting him in this very rooftop.
"Hyoudou Issei-kun."
That call was not surprising at all. Ever since he awakened his sacred gear, practicing it under Cao Cao's tutelage to a level where he could withstand Balance Breaker for a full minute, those devils in this school had started spying on him. Apparently, they wanted him to be a part of their peerage, surrendering himself as human and accepting life as a devil. Naturally, he refused. Why? He didn't need to be a devil; being a hero who would save humanity would make woman kneel before him, begging for him to add them into his harem. So, he had no reason to be a devil. Besides, devil's human's enemy. They tempted human into doing bad. There's no way Issei would be a devil.
"I'm not interested being your slave, Gremory," said Issei, crossing his hands on his chest. "Well," Issei stared at those surreal sizes of flesh hanging on the red haired girl's chest hiding behind thin cloth, "if you want to be my first harem then perhaps I'm willing to consider your offer."
"This is my territory. Human with Boosted Gear like you can't roam freely without my permission. I hope you consider it, or I'll be forced to expel you out of this school and town."
"As far as I know, this land belongs to Japan, a country of human race; devil has no right to claim it as yours. How shameful, but as expected of devil."
Now, now, Issei was not being a bad guy here. He was merely stating the very fact that devil and other supernatural beings had been ignoring. That was also the reason why Issei agreed to join Akatsuki. This world belonged to human. Human's the king of this world. Though, that didn't mean Issei hated other race for stealing it. Heck, there's no way he would hate a beautiful woman with big breast. It's just that, human's the king, they should be in control.
"I…I'm okay with letting you be my…my first-time, though we will do it after I win the rating game. However, I can't promise I will continue being your girl. In return, will you become my peerage's member? Also, I've said it numerous times that we, Gremory Family, treat our peerage as family, not a slave!"
"You really thing that I'm a disgusting pervert, aren't you?" Issei growled at that "yes"-looking look. "I'm a proud pervert, but I am a good man, and a good man should never touch a woman unless they share the mutual feeling."
"…I see…."
Issei sighed and averted his eyes down below the rooftop. Yet, no matter how much he stared at those women, no one exceeded the woman next to him. As a man who dreamed to be a harem king, letting a fine woman such as Rias Gemory into another man's hand left a bitter taste in his heart. What should he do?
"…What if I learn to love you step by step, would then you become my peerage?"
…Later that Day…
Issei was at dilemma: would he accept Rias offer, or will he continue paving his path through Akatsuki?
His hero-wannabe's side wanted him to continue paving his path through Akatsuki. That way, he would become a hero to human and no girl would refuse to be his harem. In the other hand, becoming devil would grant him everything he ever wished, plus Rias Gemory and probably Himejima Akena, and perhaps Tojou Koneko, too. Besides, becoming devil would allow him to handle more power of Boosted Gear. If he became stronger and stronger, who would stop him if he chose to save human?
…However, should he become a devil, it was the same as betraying Akatsuki who had helped him and showed him the truth of this world. If there's one thing that Issei was not of, that's a traitor. They would not forgive such thing; no doubt Cao Cao would hunt him personally. Or worse, that frightening woman, Leader's partner, would end his life forever.
"I'm sorry, but are you…Hyoudou Issei-san?"
Issei's eyes blinked twice. It seemed he was so deep in thought that he didn't felt the presence of this…pretty blonde girl cladded in Akatsuki's robe?
"I'm Asia Argento. I have been learning under Leader-sama for a few years, today is my official day becoming a member of Akatsuki, nice to finally meet you, Hyoudou-san."
Okay, who cares about Rias and Akeno when I have a pretty innocent blonde teen as my partner in the road of saving humanity?
"Yes, I'm Hyoudou Issei, I'd love to have a da—i mean to show you around while we introduce ourselves to a more personal matter, what do you think, Asia-chan?"
-End of Chapter-
This is an AU based fiction, will not follow the flow of canon story, at least not all of it.