What if at the end of the anime version of Kateikyoushi Hitman Reborn as an after effect of Byakuran's defeat the Rain Guardian ring, along with Jiro and Kojiro's box, was pull through a rift in time and dropped into the hands of a 11-12 year old boy with dreams of becoming Hokage.
Guidelines
1. Due to the rift the Ring of Rain will hold the memories of Yamamoto's sword style, Shigure Soen Ryu, which Naurto will receive as time goes on.
2. His mastery of the style will progress at a reasonable pace, no god-like Naruto
2a. If he gets it at the start of the series
2ai. He will master the first eight forms by the battle on the bridge
2aii. He will gain the 9th form by the Chunin exams
2aiii. He will get the tenth form and 11th forms along with Squalo's Attaco Di Squalo by the third round of the Chunin exams but after the 2nd round
2aiv. He will gain the ability to use the vongola box fully during the search for Tsunade
2av. He will get the True Guardian Status during the time skip or during Shippuden
2vi. Naruto creates a new form after he learns the 11th form at a time of your choosing.
2b. If he gets it in the forest of death or during the month of training after the 2nd round of the exams.
2bi. He will have the first 9 forms by the fight with Neji.
2bii. He will get the tenth form and 11th forms along with Squelo's Attaco Di Squalo during the search for Tsunade
2biii. The ability to use the Vongola box will be received in the time skip
2biv. True Guardian status will be gained in the elemental Training arc
2bv. Naruto creates a new form after he learns the 11th form at a time of your choosing.
If anyone says that these are too fast paced, stop and think about how long Yamamoto had to train for the Ring battles, for the attack on the base in the future, for the Choice battle and how long it took to get the True Guardian status for the final. So if anything this is agonizingly slow.
Also you can give Naruto the Shigure Kintoki
3. Chakra is actually a form of Dying Will Flames, but heavily watered down with physical energy. It works by the Flames creating a lattice work which the physical energy fills and acts out the purpose of the Jutsu. This means Naruto's Rain-type flames can interfere with Genjutsu and Ninjutsu by using the tranquility attribute to lower the speed and power of the supporting flames.
4. The Flames don't influence elemental affinity, just what type of fighting styles a person is suited to. This means the five affinities are determined by the physical energy. What abilities the flames give to the user:
Sun=Medical and Hand to Hand (so Sakura and Lee are Sun types)
Storm=highly versatile selection, with the heavy artillery type attacks, (center guard in MGLN terms, don't get the reference look it up) (Kakashi is a Storm/Cloud hybrid with an emphasis on storm)
Mist=Illusions (Kurenai is a full mist type)
Cloud=adaptability/going without support (Zasubasa is a cloud type)
Rain=out of the box tactics and influencing the actions of other, improving team morale (Naruto is a rain type in the story though he seems more like a sky/thunder/sun mix)
Thunder=being the center of the fight and taking damage for the rest of the team (Killer Bee is a thunder)
Sky=non-elemental attacks, speed and seals, with leadership abilites (Minato is a Sky type)
5. The story will primarily be canon but Naruto will have to fight off Byakuran's reincarnation from collecting the remaining parts of the 73 policy which he needs to jump to another reality since the current one is a total failure. This can be minor or major depending on how you do it.
6. You are allowed to reincarnate the Funeral Wreaths, but they must remember the circumstances of their death.
7. Naurto is the only Dying Will Flame user beside Byakuran if you don't reincarnate the Funeral Wreaths.
8. Allowed pairings Naurto+Hinata, Naurto+Tenten, Naurto+Ino, Naruto+Sakura, Naurto+Bluebell (she will be the same age as Naruto) if she defects, Naurto+Kin, Naurto+Tayuya or anyone Female within a reasonable distance of Naurto's age. No Male+Male pairings.
9. An afterthought: if you go with the 2-a approach then why not do the Byakuran arc during the time skip. Meaning you have to write about Naruto's training in this time and have him encounter each of the Funeral Wreaths, one at a time until only Byakuran is left. Also a good time for Bluebell to defect. I can easily picture this kind of scene for the beginning of her defection:
Bluebell closed her eyes waiting for the final blow. She heard a thud next to her left ear and slowly opened her eyes. She was shocked to discover Naruto standing over her with his sword thrust into the rain soaked ground by her head with a sorrow filled expression on his face.
"Why?" he asked as he fell to his knees by her side. "Why do you have to fight for someone so willing to betray you and throw your life away while refusing to see how much you care for him?" Bluebell opened her mouth to give a retort but the words died in her mouth as she realized that he was right, Byakuran, the man she would willingly giver her life for, simply saw her as a disposable tool and toy. Tears started to well up in her eyes as she realized this. Naruto gathered her up in his arms and cradled her as she wept at how her world had just been shattered by that single question.
Darn I started to cry just writing that.