Naruto Uzumaki ran. He ran like all hounds of hell were after him. No It was not Akatsuki. And it was not a mission. And no, he did not piss off drunk Tsunade. It was his first day of high school and he was late. The road to school was quite a long one and he only had ten minutes. And as to how he got to go to a high school, being a shinobi and all, not to mention the lack of high schools in fire country and shinobi nations in general? Simple. He was no longer in Fire country, nor was he anywhere in the shinobi nations. How did that happen? Well...
The three years training journey with Ero-sennin Jiraya were coming to an end. They were travelling through the Tea country, after their Jiraya's "Work-related" visit to Haha Island, to be precise Jiraya went there to discuss the release of additional "Collector's Edition" Icha-Icha Paradise and Icha-Icha Violence. And that cheap free-loader cleared out his Gama-chan. Again. Despite having more than enough money himself to get drunk and to go to the Red-light district. Several hundred times. Not counting the money he did not carry with him. So Naruto was in a pretty bad mood and just continued to insult the perverted hermit most of the time they spent getting to Tea country.
Somewhere between insulting each-other and arguing about where to stay they bumped into Kakashi, who was returning from the mission in the south of Tea country. This elevated Naruto's mood enough to forgive Jiraya temporary. They decided to return to Konoha together, even though it would be a month earlier than planned. They stayed for a night in a hotel and early in the morning set out for Konoha.
The trouble came unexpected like French Inquisition, big as Life and twice as mean. Itachi Uchiha, Hoshigaki Kisame and two other Akatsuki members were big trouble even for the three of them. The battle was a hard one, but everything was fine until Kakashi started using Kamui. He tried to draw in Kisame, but instead when Kisame flung Naruto away from himself... Naruto flew straight into the path of Kakashi's technique. From that point on Naruto had no memories until he woke up in a forest on a mountainside.
Luckily for Naruto he came into the world at the beginning of summer, so for a few weeks he hid himself in the forest and scouted the surrounding area with Kagebunshin. During these weeks he learned that luckily for him his native language and the language spoken in the place he found himself in were not very different, in fact all the differences came from cultural and technological differences of the worlds. Which was still a lot. But Jiraya taught him, bashed one single thing above all else into his skull : SURVIVE. ADAPT. OVERCOME. BENEFIT FROM ANY SIUATION YOU FIND YOURSELF IN.
So Naruto survived, adapted and overcame. He lived off stealing small amounts of money in the crowds. He learned the ways of the new world and continued to train and become stronger, although he could not train most of his offensive techniques, he perfected his chakra control as much as he could. He Learned all the things, well nearly all that someone who was born in that world should know, to the point that his Kagebunshin were no longer attracting attention and could freely talk with strangers without appearing to be foreigners or showing the lack of common knowledge.
The hardest thing for Naruto was his loss of ability to Summon Toads, as that was his last hope of receiving help from home. But he eventually accepted that he was stuck in this world, until he could make a reverse-summoning seal that would take him to Myobokuzan. Which was not for the next decade at the very least he was sure. So he decided to Go to high school as he was still fifteen and that was the typical age when teens went to school here. So he choose a kind old man who lived alone and was lonely, because his family did not visit him very often. From what he knew of the man his relationship with his own daughter wasn't a close one, but he had a grandson named Kouta, who sometimes visited him and loved his grandfather, who coincidentally was he same age as Naruto. So one day Naruto had his Kagebunshin beat himself up black and blue and dump him in the middle of the path the old man usually took whenever he went for a walk. He plan went off without a hitch and Naruto feigned amnesia and got taken in by the old man. He then asked the old man to enroll him to a High school, telling the old man he wanted to start a new life as he did not remember the one he had and promised to pay him back as soon as he could. Yoroi Akamon, being a very kind and trusting old man, agreed to help Naruto with the money. (A/N He and his daughter just have very different outlook on the world, hence the distance between them)
Naruto barely made it in time for the bell. The first lesson was uneventful, the teacher gave him ten minutes to introduce himself and answer any questions his classmates had, then went on with the lesson. During the break a bespectacled girl came up to his desk and spoke to him "Are you okay, Uzumaki kun? You didn't get anything to eat..." Naruto looked up at her, smiling, scratched his neck and answered "Ah, well... I'm just not hungry is all, no need to worry, mm..." The girl smiled back at him "I am Akane Asahina, the class representative, if you need anything just ask me." Naruto continued smiling "Ah, I don't want to be a bother, Asahina san, but thanks anyway". Suddenly the door to the classroom opened, attracting everyone's attention, and a beautiful black-haired girl walked in.