(11th October, year 50 after Konoha establishment)
After Chitose left and Yuta was able to finally relax a little, he felt that a great amount of tension that he wasn't even aware he had built up inside, that was pressing on him from the moment he found himself in the black void, finally started to ease up.
As the tension eased and Yuta relaxed, something unexpected happened. Like a wild beast sensing a weakness when he relaxed, a mix of intense emotions hit him. His whole body started to tremble as intense fear gripped his heart, deep inside he felt vulnerable and helpless, he suddenly wanted to cry and call his mother, he recalled his mother's warm smile with desperate longing... Hiromi Arai...
'No! This is wrong!' Yuta thought, trying to suppress his emotions with a sense of urgency, 'Hiromi Arai is not my mother! I'm not actually Yuta, these feelings aren't mine!'
...
After a while Yuta managed to calm down.
"... Yuta!"
'This is not good, the memory merging process fucked up my mind, I must solve this somehow or I will become this Yuta kid for real, inside and out, I can't have that!'
"... Hey Yuta!"
...
"Hey Yuta! Snap out of it kid!" Chitose's hoarse voice sounded nearby, she was returned at some point and was calling out for Yuta for a while now.
"Huh" Yuta finally noticed Chitose standing beside his bed, looking at him sternly, but also with a little bit of pity.
"Everything will be all right kid." Chitose said with a bit of warmth sipping into her hoarse voice, "Now tidy your bed, the lunch will be ready soon!" Her usual stern demeanor returned as if there was never any warmth or pity in her to begin with.
"Yes, Koba-san." Yuta hurriedly replied and started to tidy his bed under Chitose's stern look.
With that Yuta's new life in the world of shinobi has finally begun.
...
Two weeks have passed since Yuta first woke up in this world. It was a boring and uneventful two weeks, filled with tension in the air and in his own mind. The mood of the people was gloomy and heavy due to the many casualties in the village. The caretakers of the orphanage were tense, the orphanage was understaffed for so many kids suddenly pouring in, and those new kids were scared and restless.
A lot of new kids were brought to the orphanage during this time and only some of them later were taken away by their parents. The whole village seems to be in a mess and disarray.
From what caretakers occasionally talked with each other or with parents that come to pick up their kids, Yuta heard that the damage to the village was immense. A lot of people are dead, a lot of people are missing, unknown if they were dead or alive, a lot of unidentified bodies in the wreckages, a lot of injured people at the hospital... At the end of the second week those who are missing and not found yet - being declared dead.
Apparently, a few whole areas of the village were raised to the ground during the Nine-Tails rampage, hundreds of residential houses were destroyed, casualties among civilians numbered by thousands, and there were heavy casualties among the shinobi as well.
But as time went by, the situation started to gradually calm down.
Initially Yuta was agitated and nervous after he woke up in this new world but after a while he came to acceptance of his situation and his new life as Yuta Arai in a world of shinobi.
The memories of the original Yuta were integrated into him seamlessly and there is no problem with how he acts and speaks in a new world, how he is using new language and completely different set of traditions and social norms, it feels natural to him. He knows and understands everything that a child native to this world of shinobi should.
During this time Yuta sorted out his memories that were merged with the original Yuta kid and learned how to behave like a native of this world while cutting off all the remaining traces of the original Yuta's personality. He didn't forget even for a second that he is an outsider in this world and felt repulsive towards the idea of embracing the original Yuta's personality with all its emotional bonds and stuff, especially now, that it's being two weeks and Hiromi Arai most certainty dead.
Even though no one told him anything about his mother being dead, but the lack of answer for the whole two weeks is an answer on its own.
Besides fully embracing the original Yuta's personality and becoming him in a true sense will be the same as destroying his own personality and everything who he is. With that mindset he accepted the name of Yuta Arai and memories of the original Yuta, but spared no effort to get rid of everything else, like emotions that those memories were intertwined with, as well as all the bonds the original Yuta previously had with his parents, friends, and the village itself.
He had to do all that, there is simply no other choice.
From the original Yuta's memories he inherited, there also were memories of his father educating him and influencing his views towards the village, his father taught him how great the Konohagakure village is, and how everything should be done for the betterment of the village and all that... His father was a shinobi of the village, recently promoted to the rank of Chunin, and he was fanatically loyal to the village.
All those teachings greatly influenced the original Yuta, who accepted those views by heart, and then passed all of it to the current Yuta. If the current Yuta didn't cut off all those views, bonds and emotions, he would've been compelled to go straight to the Hokage and directly report all that he knows about Naruto plot... He can't have that...
He didn't want those bonds and emotions to influence his future actions and judgment, so they had to go.
During this time Yuta mostly stayed indoors, usually idling on the bed or somewhere in the corner, so no one would disturb him while he was sorting out his mind. He might've got the reputation of a gloomy and unfriendly kid that deeply grieves about his parents, but not that he cared about such things as what other kids and caretakers think about him.
After sorting things out and clearing his mind from the unwanted emotional baggage of the original Yuta, he thought of what comes next. Naturally, the idea of enrolling into the Ninja Academy comes to his mind. Especially now that he overheard that many kids in the orphanage talking about ninja academy and how they can't wait to become ninjas. And caretakers openly support and encourage it.
From what he overheard, the minimal age for enrollment being 5 years, but most kids usually enroll at the age of 6, as there is an entry exam in place and by the age of 6 kids apparently have better chances to pass. Apparently, one has to be physically fit to enter the Ninja Academy, and 6 year old kids could naturally outperform the 5-year-olds.
Keeping that in mind, Yuta decided that starting the next day he will begin training to successfully enter the Ninja Academy in the future.
He overheard that Ninja Academy holds the entry exam in April, and since it's October and Yuta was only turned 4 years old recently, he won't be able to enter the academy in April next year, as it will be only in a half a year's time and he won't be 5 by then, he can only wait another year for that. That means he has one and a half years until his entry to the Ninja Academy.
As for his chosen starting gift as Time Control ability, he didn't forget about that either, he was just too preoccupied with sorting out his mind after the memory merging messing him up, he had to concentrate on that just to not go crazy with all the emotional mess it left in his head.
The next morning Yuta woke up due to some commotion in the room that he shared with a bunch of other kids. After he sat on his bed and looked around, he saw that half of the beds were empty, that's around thirty or so kids were missing. The other kids that were present is only started to wake up.
Looking around, Yuta thought confusedly, 'It's still early in the morning, they wouldn't wake up that early and go outside by themselves, and even if they did – it won't be without making a sound...'
"Where is Tsuyoshi go?" One of the kids asked confusedly looking at the empty bed, "Where is everyone?"
Similarly confused sentences could be heard all over the room, but then Chitose comes into the room and says loudly and sternly, "What is this all about? Calm down and behave, kids!"
"But Koba-san!" One of the kids interjected anxiously, "Where is Tsuyoshi, and Hiroyuki, and others go?"
"Ah, that's what this is all about." Chitose said dismissively, "They were all taken by their relatives last night. Now stop this unruly behavior, tidy your beds then go wash up and get ready for breakfast!"
With that, the commotion subsided under Chitose's stern gaze, and the kids busied themselves as if nothing happened.
'Huh, what a bunch of crap!' Yuta thought while getting up.
'And everyone believes in it just like that and didn't question anything... Around sixty kids went to sleep last night and only around thirty remain in the morning, and you say they were taken by the relatives? Without waking up anybody in the middle of the night? And a bunch of "relatives" suddenly shows up at night like that? What an utter bullshit!'
'It seems that those that are missing are mostly the older ones, from the age of four or five and older... Among those that younger – not a single one is missing... And not everyone that are older than four is missing, some of them are still here...'
'What's going on in this damn orphanage?! Chitose clearly knows something and hiding it... I hope I won't go "missing" too one day... But what can I do? Run away? To where? And what then?... Sigh... No point thinking about this, I can't do anything in this situation...'
'Other kids don't seem to care that much about what happen and actually believed in the "relatives" explanation without a second thought... Well, they are just stupid and naive kids, whatever an adult says must be true in their world view... '
...
'Kids... I wouldn't make many friends with the kids my age, wouldn't I? I just won't be able to blend in and behave like they do. Anyway, it's still a long way before Ninja Academy, and as for this orphanage – what the point to even try to make friends among the kids here?'
'I'm used to being in my twenties, acting like a kid and interacting with kids feels weird. What would I even talk about with them? They do not even talk much, just running around, screaming, laughing, throwing around childish insults and talking naive nonsense... No thank you!'
Yuta's mind is clear now, the first goal of entering the Ninja Academy is set, and the plans to start training are formed, the new day has started, and Yuta is very excited about his new life for the first time...
--- AN ---
I hope I didn't bore you too much with all the world building and a slow start like that. There is a bit more of it coming though before the action starts, I hope you can bear with me through it, I don't really want to skip this initial part of the story and jump straight to the post-academy times, as there might be time-travel being involved with this events later on (not spoiler, just a possibility).