Zenko; Feral

Reunion

Ever since Naruto ran off from the ANBU Headquarter, he has been living in the forest. Using what Minato taught him, he claimed the forest as his domain. The animals there could sense his feral chakra and most avoided him. The ones that aimed to kill him were those whose superiority felt threatened.

Minato advised son to avoid their area. Naruto may have strong chakra but he has no experience in wielding them. He also noticed a difference since the day Naruto was struck by the Raiton Jutsu. He behaved more instinctually, like an animal. He can still think like a person and process thoughts like a person. This was proven as he could read and write from what Minato could teach him and the random rotting books or scrolls scattered in the forest.

Naruto could formulate ideas and plan for things like hunting or sleeping accommodation. He can listen to orders from Minato and he can learn from his trapped father. But he does not process it the way a human do. He processed the whole thing like...an animal. Like a dog from the Inuzuka kennel. He could do all those things but he could not process the whole thing like a human would. He could not speak like a human and he behaved like an animal.

It took a lot of training from Minato for Naruto to gain even a little bit of the human child he once was like hygiene and self-care. But he's clean in a way a domestic animal was clean. For the sake of safety, he seldom washed. His clothes remained dirty and tattered and soon, he was only wearing a wrap around his hip since they were not made for an outdoor life or an active one either. Propriety was something Minato refused to let Naruto forget.

Winter was the worse. But it wasn't because of the weather but rather the lack of food. Everything froze and animals hibernate in their den, making hunting and foraging for food hard. Naruto's hands and feet, already furry, grew dark red as the furs there thickened to cover his extremities from the frigid temperature as he dug through the frozen ground for food. Naruto's chakra kept him warm but his hands and feet made constant contact with the frozen nature so his body adapted.

His claws blackened and hardened to better protect his fingers and toes, the padding of his feet also darkened looking more and more like a fox. He no longer leaves the footprint of a child but a fox. A large fox but a fox nonetheless, making it harder to track him on the ground.

Like the dogs of Inuzuka, Naruto can use Kawarimi and Henge. He has trouble with Bunshin but Minato decided to teach him Kage Bunshin instead the moment it dawned on him just how miniscule the chakra cost of the ordinary Bunshin was. It would never suite Naruto. Naruto's Henge also differed. Instead of simple illusion, he could make a solid Henge.

Out of boredom, Naruto started to play around with the three Ninjutsu he learned. He started swapping it around and made a game between him and his clones. Henge and Kawarimi and Bunshin swapped in so quick a succession that he could confuse his enemies, a tactic he used when faced with the forest's top predator to get away from danger.

Minato was impressed with how versatile Naruto used what he learned from Minato. Combined with his speed, he was never caught...until he ventured too close to Konoha and came across the girl that he met once when he sought shelter in the abandoned shrine. It was a reunion that once again changed his life.

It was winter.

Three older boys surrounded her and mocking her in horrid tones. Naruto didn't speak human with Minato and Minato didn't realize this until they came across the girl and Minato realized that Naruto understood the whole thing from the tone of voice and not the words. But whatever the boy said, it was clear he was tormenting the Hyuuga girl.

From living in the forest, Naruto behaved as one of the residence of the forest. He picked up the battle style of numerous animals to survive and he used the mountain ram head butt right into the mocking leader's stomach, knocking him out cold. While they were bewildered, he grabbed the girl and ran off into the winter wood. She squeaked and called a familiar word, "Naruto?"