I do not own naruto anime, manga or other released formats.
I guess some clarification is needed, sorry for the trouble. I am well aware that in reality the biju are in fact were divided from the ten tail beast, which in reality is a basic part of nature. But in this story each biju was initially called a demon, and so they took the title of ruler of a circle to scare would be attackers, as they grew older they took the role as a way to test their jinjuriki's bravery and resolve. Fear can be a powerful tool, and these 9 learned to master it. As to why he never met Kurama sooner he had lived a pretty peaceful childhood. As for why Kushina never met Naruto is simple. Naruto spent most of his time in the clan grounds which he either did training, or spent time with Mikoto and the family. Mikoto is an unorthodox uchiha she would form friendships regardless of clan. Naruto is more orthodox and knows full well that the Senju hate them. Uzumaki is technically a branch famiy of the Senju. Even Madara in the place Naruto was first conceived, met the Uzumaki after he left to why they did not met in the Academy different classrooms. And if you are wondering yes Tsunade will be a very much Uchiha hating Senju. I hope that you enjoy this story and like always I welcome suggestions.
"Hey, sis what is going on?" Naruto asked the snarling biju. "It seems for some odd reason the biju in that girl Kushina wants to pick a fight with me! I am not one to run from a fight, and I know neither are you!" Touch her shoulder and I will take us to the place of our duel." When Naruto touched her shoulder he felt the malice of the biju, but it did not scare him. He and Kurama appeared in a field of burning trees and they both understood this was made for him to take out some of his pent-up anger on something. For him to use his jinjuriki to demand a fight just went to show how angry he was at sensing them. The image of Kushina and a very angry kurama, the only difference he could tell physically was that he was a he and had black messy fur.
The Kurama that he knew, the one that during his missions took to calling his big sis, was female. She always took great care of her red fur, silky as smooth. She might have tried to scare Naruto or even tested his bravery or if he had confidence in his strength but as the war started he was happy with her jinjuriki and was very much the loving big sister, that she always wanted to be. "So you even go as far as to pretend to look like me!" She just gave him a nasty glare, "Mine vs Yours If one biju is defeated that biju agrees to seize to exist. There can only be one!" Naruto walked up to the angry biju and told him in not a nice way, get on with it, but if that Uzumaki was thinking that she was going to have an easy fight guess again. Naruto activated his magenkyou sharingan. "She interferes in the fight, and I will stop her! She tries to help you and I will stop her! You want to fight my big sis then it better be on even terms or else!"
The black kurama liked the way this young man did not go around the bushes. He was as direct as he was, and without even saying start he attacked the red kurama. Both jinjuriki walked to a nearby place where they could see the fight and not be in the way. "Look I know who you are, Mikoto would not stop talking about you, but how about we try to remain civil? I don't like this anymore than your do." Kushina tried to have a chat with Naruto. He looked at her and replied, "My grandfather left an imprint of his mind, to teach and train me. His opinion was that most Uzumaki were very much like the Senju. He only trusted 2 Uzumaki out of the entire clan. His wife, and sister in- law. That tell you the warm and friendly opinion he gave me about it."
"Mikoto always wondered why you avoided me and the Senju. Guess it was to be expected. You can turn off your doujutsu. I am not going to get in the way of Kurama and his fun. You might not like my clan but we are an honorable sort. Once we promise something we always keep it. I promise not to interfer with the duel or the outcome, Dattebane!" Naruto looked at her trying to believe her, so he did turn it off but could reactivate it in a second.
The fight was your standard brawl. Bites, swipes, kicks, snarls, and more dirty tricks from the black kurama than Naruto and the red Kurama could care for. The black biju was brutal and attacks in any way he could. He even took some of the branches of the trees and tried to used them as weapons. The red Kurama was doing her best to win this fight, but you would sooner expect Jiriaya to jump naked into the men's hot spring declaring himself gay that her fighting dirty during an honorable duel.
To Naruto the fight was not going so well, the sheer brutality of that black Kurama was something. He was pushing his big sis and the strain was showing. The last second he threw dirt in her face blinding her, and before she could even react he tried to used the beast ball attack. But he did not count on her hear the attack power up, and he missed only to have the very attack redirected by one of her tails which set it right back at him. The attack hit him on his head, knocking him out, she just walked over to him and sat down.
"I though I said it was to the death, why didn't you finish me off?" The red Kurama was taking care of her fur when she noticed him awake and asking a dumb question. "We both know that we can't be killed, so stop with the pretending already! my bro is honorable what did expect that I would be any less?" The black Kurama stopped pretending. "So he treats you right? doesn't just use you for your power?" The red Kurama gave him a big smile. "My bro is as sweet as they come, and that blonde bro of mine would never even ask for it, he waits for me to offer my knowledge or power." The black Kurama had to admit that was nicer than any of his past jinjuriki. "You win, I will give you mine entire chakra, use it and keep those precious to you safe." Kurama could swear that she heard the black Kurama snicker was it was absorbed into her.
"Well Naruto, I am now I am twice are strong as before. Bro why are you laughing like that?" Naruto simply pointed at her fur and she immediately noticed something was definitely wrong, wait a minute it looked like... "Ah, what the hell, my fur is all a mess now! It is going to take a couples of weeks to clean it, and get it decent again. Hey, Uzumaki! Did he ever hear about taking a bath this smell could kill of a skunk!" Kushina was not able to answer for a few moments, why you ask. Because she was laughing to hard. After she was done and could answer she just mentioned to her did she see any place where he could take a bath in? Now Kurama really appreciated her bro making a full apartment for her behind the seal gates.
When they both left the mind of Kushina it hit him hard. The extra instant increase of chakra cause him sever pain, as his chakra pathways expanded, and Kurama was busy doing her best to heal him. But not quickly enough. Naruto collapsed on the ground and was then that the entire camp saw a very frantic, worried, and angry Mikoto screaming for medics. The medics came and took him to the field treatment tent. When they told her that she needed to wait outside, she just did not listen and went to wait by the available place. She waited to the doctor finished healing him and was practically praying and almost crying all the time she was waiting. Kushina did not know what to do or why would she react his way. It was almost as if the two were lovers. Strange wasn't he supposed to be her adopted brother?