Naruto world :
In an empty place where blood was flowing like river's and full of death energy there is a man with yellow hair breathing his last breadth thinking about his past and leaving his son to get rid of trouble but he had some regrets that he couldn't become more strong to help his son in this war.
As he was thinking a voice called him. After hearing this he called kurama what do you want I'm in my last breadth so this will be my good bye.
[yeah you are on the verge of death but fool I will help you by performing rebirth technique by using your six path energy and my complete chakra. But remember only my soul will accompany you to reach my level of power might take some months/years. So get ready to hold your dear things.]
Thank you kurama I will collect as much as natural energy possible for this jutsu.
While this was going in this world.
In another place of a void. A soul is sitting in the presence of a old person. He was checking the details of this person
[son what a pitiful person you are. You have greatest mind in the cultivation world but you still could not cultivate and at last you were killed by your family. So I will send you to earth you will get a gift when you become seventeen years old. So get going and enjoy your life]
Thank you for your kindness replied the soul.
God inner thoughts( now here I sent a yin soul by almighty command what is he doing now with this soul.)
When God was thinking he felt another soul pass through void but it didn't stop near God it went to the same direction of yin soul. And tried to stop it but unknown forces are stopping him. So he was helpless.
But what he saw afterwards made him shock because they both combine and form yin-yang soul. One of the strongest soul in soul legend's.
*******
While he was thinking this kurama jutsu failed as they went of course an went to earth where a woman is pregnant. If you see her clearly she looks like kushina and a man standing beside her look like minato. But who know until our mc is born so. Let's wait.
Just like that 9 months passed away and our mc is in deep sleep because he combined with new soul. But there is a surprise for him when he wake up because kurama is still in naruto mind space although it is weak but still has some chakra left so it started nurturing the naruto soul as it felt familiar.
The familiarity is due to kurma power itself related to yin-yang but when naruto was in void he combined with yin soul to form yin-yang soul.
Due to the nurturing naruto soul purity increased very much. As today naruto is going to born kurma didn't nurture the soul and took rest until naruto wakes up.
In front of the operation theatre you can see a man full of worry moving side to side. When he saw the light went off and he didn't hear any voice of a child, his face become pale. The nurse was running to get instrument to make the child cry as they are hearing the heart beat. As they used the instruments naruto who was in deep sleep woke and saw he was in pain so he started to shout at these nurse as he is going to be the future hokage at least they must take care of him gently.
(AN: Naruto you such a fool)
[fool we are in different world there was some foreign force that made you rebirth here and now we are going to live here.]
Naruto : kurama what you said we are in different world not in our world. As he was asking for answer's. Naruto was in great pain as memories of another soul got integrated in him.
SO that's what happened. It seems we are stuck here and I'm going to live my life again as he was took away from room and cleaned him and brought to his mother chamber. He was shocked by what he saw his mother was same like his previous.
While he was thinking about his past life. His mother took him in to her arm which made him calm and had a feeling of familiarity. Then another man entered in the the room again he was shocked to see his father to be same as his previous life and their names were matching too. He was confused and was happy to have them in this life.
Minato asked his wife to name him she named him Naruto. This again shocked him. When they were naming him minato and kushina saw him to be shocked but they can't know what he was thinking.
As the family was happy having a son. Which reminded them of some one but they can't remember it.
Naruto: as this is new world I need as much information as possible of this world.
As such our mc determined to get information. But when he went out of the hospital he was shocked to see sky scrapers, cars etc. In this way he got some information in six months. That this is relatively peace world compared to his previous one.
1 year passed away. He was able to talk and run in the house. His father and mother was happy for him being genius.
Kurama also taking rest and gathering nature energy which was more powerful than chakra. It needs five year's to completely recover.
Two years passed like that. As he was passing his days like that by reading some higher class books and doing simple exercises. As he was doing his daily work. He heard a voice from his partner.
[ oyy. Naruto don't waste your time this world may seem peaceful but there are lot dangers as the energy I'm collecting is lot more powerful then chakra(at least 5 times). So I want you to refine your body by using asura body cultivation technique as I nourished your soul and body when you are baby. So this technique should play the trick. It is said that those who practise this technique will have bodies on par with God's.]
When I heard kurama said that I read the technique it passed on so I started to cultivate this technique.
When I was cultivating this technique a strange energy was refining my body on it's own although I may have young body but I can judge the nature's energy. But it seem something different in this energy. I can sense some nature energy and other is life energy.
(so what kind of changes would this technique bring naruto)