I do not own Naruto or Jujutsu Kaisen.

They belong to their respective owners.

This is just a fanfiction, don't take this too seriously.


Konohagakure

"Let's go Satoru, the admission for the Ninja Academy is today. If you don't get up now, then I will drag you there along with the fuuton." Hatake Sakumo calmly reminded(threathened) his son.

"Okay okay! I'll get up now." said Hatake Satoru hurriedly.

After all, Satoru knew his father would really drag him all the way to the Academy with his fuuton when he's serious like this. Satoru remembered the time when he doesn't want to study the basics of Shinobi Rules because it's boring, his father actually took away his pocket money and all the desserts in the house until he would study properly. Truly a strict father, after that event Satoru can no longer afford dismissing his father's threat, at least until he's strong enough to get away with it.

Half an hour later

"Hey Dad, is it really necessary to study at the academy? You probably already taught me most of the stuff they're going to teach there."

"Satoru, you must graduate from the academy to be officially a ninja, and I will not pull any strings for you to skip that process. It's also a good place for you to make friends. Who knows? You might even meet your future sweetheart there."

"Hehe, that remains to be seen. But hopefully, it won't be too boring."

As the father and son duo walked through the streets towards the academy, they were greeted by some of the passersby.

"Ooh Sakumo-san! it's good to see you today. Are you going with your son for the academy admission?" said by a young ninja passing by.

"Yes, we are. I'm kind of curious myself to see Satoru future classmates." said Sakumo.

"Ahhh, I see." the enthusiastic ninja replied.

"Hey Satoru-chan! Here's some candy for you, hopefully you'll make lots of friend in the academy." said by a friendly auntie.

"Don't worry I will! Thanks for the candies auntie!" said cheekily by Satoru.

After the small talk with the passersby, Sakumo and Satoru quickly resumed their journey towards the academy.

Hatake Sakumo's reputation nowadays is famous throughout not just Konoha but also most of the continent, thanks to the Second Shinobi World War where he got his moniker Konoha no Shiroi Kiba (Konoha's White Fang) from his extensive use of the White Light Chakra Sabre. One of his famous exploits includes his victory over the son and daughter in law of Lady Chiyo who's known as the leader of Sunagakure's Puppet Brigade and a poison expert. His skill and fame overshadowed even the legendary Sannin, only ninjas of the most elite calibre would dare to face him in a battle. Some people even speculate that he is likely to become the next Hokage after the Third Hokage retire.

Then there is his only son, Hatake Satoru. Born to such an outstanding father, expectations were high for Satoru from the start. There would be three things that come to people's mind when Satoru is mentioned.

First, he's definitely gonna grow up to be an extremely handsome man, many young men would lament their fate to be born on the same era with Hatake Satoru while many women would rejoice their fate being born on the same era as Hatake Satoru. Satoru had a natural born white hair just as his father had, he often spikes them up when he's wearing his blindfold but lets it down when he's in a more casual occasion. He inherited the good look quality from his father and his mother, giving him the perfect face to make females fall in love at first sight. His body type seems to be growing up towards a lean body type, but with his father's caring(strict) training regiment, he's shaping up to be a very healthy and fit shinobi.

Second, he's a genius among genius. His father had been strict in training him from the very beginning, and Satoru simply surpassed his expectations everytime. While most ninja starts to learn on how to mould their chakra at the academy, those from a ninja family background usually taught their younglings earlier and guide them with better methods than what's normally available to the common ninja. Even then, it still takes some time for someone to successfully mould chakra, generally the sooner you succeed the better your talents are.

When Sakumo taught his son how to mould his chakra, Satoru succeded on his very first try, leaving his father speechless. A few days after, Sakumo taught his son the tree climbing method to train Satoru's chakra control. Satoru simply walk up the the tree after Sakumo's demonstration with no difficulty at all, once again leaving his father speechless. The same thing becomes a routine when Sakumo teaches the three basic jutsu to Satoru. After that Sakumo decides to teach the more theoretical parts of a ninja curriculum such as the Shinobi Rules, and he was relieved to see that his son is not as invincible as he thought. At least Satoru's laziness towards things he consider boring makes him more human and will be there as an obstacle Satoru needed to overcome in the future. Of course, Sakumo only let out a few things to outsiders about his son's incredible talent with some alterations made. After all, being too outstanding may cause some unwanted attention and action from others.

Third, Satoru has a dojutsu type kekkei genkai that he named Rikugan. It manifested in the form of a very beautiful light blue eyes, those who saw it will be unable to help but feel mesmerized by those eyes. When Satoru came up with the name, his father asked him the reason behind that name and Satoru simply answered that the name just appears whenever he's thinking about the eyes name. So far what most people knew of its abilities is the extraordinary vision it provides, it gives Satoru the abilty to see things even from a very far distances. It even works while Satoru is wearing a blindfold. But in fact Satoru's eyes can do a lot more. Not just a heightened vision, this pair of eyes can also read chakra in extreme details along with it's flow within someone's chakra network. Thus it explains why Satoru can easily understand what his father demonstrate to him and do it perfectly after within a single try.

This naturally caused some questions to arise, Hatake's clan does not have kekkei genkai like this nor there was any record of them having a kekkei genkai, then the next possibilty would be from Satoru's mother family. Yet as far as Sakumo knew his late wife does not have any kekkei genkai in her family line, maybe records were lost during the Warring States era about her family's kekkei genkai, when he asked his wife about it she only knew about some rumors in her family about the ability her family once possessed where they manipulate some sort of space-time ninjutsu with the help of a legendary eyes never seen before. It's a pity his wife passed away a few months after Satoru was born. Thus, Sakumo can only try to bend the truth from the public for as long as he can while helping his son to discover more about his mysterious kekkei genkai. So far, what they have discovered is that this dojutsu type kekkei genkai is like a mix of Byakugan and Sharingan abilty, particularly the heightened vision and the abilty to understand the workings of ninjutsu and copying it. As for the space-time ninjutsu his wife mentioned, Sakumo can only remain silent about it since such ninjutsu were extremely rare and complicated, one that he ever heard of was Hiraishin no Jutsu(Flying Thunder God Jutsu) developed by the Second Hokage. It requires the understanding of the complex principles and mechanism behind the jutsu and it's too early for Satoru to encounter such things.

There's also the ability to process chakra incredibly efficiently for any kind of things that uses it, they found this a few months ago when Satoru learned how to do Kage Bunshin no Jutsu(Shadow Clone Jutsu), at first Satoru begged his father to teach him this B-rank ninjutsu since it seems like a very useful ninjutsu but knowing his son Sakumo simply told him he will not teach him unless Satoru told him what he really wanted to use the jutsu for. After being told that Satoru wants to use the jutsu to have others do the boring stuff for him while he does more important stuff(mainly eating desserts and lazing around), Sakumo takes a few moments before accepting that his son is really perfect in everything but character. In the end Satoru still got what he wanted and when he tries to figure out how much is his current limit of clones, both father and son noticed that Satoru chakra reserves is practically unaffected by the cost of the jutsu after his 10th clone. They soon discovered that the jutsu usual consumption of half the user chakra has been reduced to infinitesimally zero while retaining the usual result thanks to Rikugan and such feat theoretically could be possible to be used on any application that uses chakra, so basically Satoru should never run out of chakra from spamming ninjutsu under normal circumstances.

As a father to such an outstanding son, Sakumo sometimes couldn't help but worry about his son safety. The ability provided by his kekkei genkai would be coveted by anyone should the truth of it's abilities ever comes out. He knows that in this world, power speaks the loudest, the current Konoha is known as the number one ninja village because of the powerhouses it possesses such as him, the Sannin, the Third Hokage, and many others. The First Hokage managed to build this village because he was strong enough to end the Warring States era. At least until Satoru becomes strong enough, he will always be worried of his son's safety.

Satoru noticed his father's concerned look and knew this was the usual [My Son's Potential is Too Powerful, But He Needs Time To Grow] thought and just as usual he called out to his father.

"Father. Don't worry about my future, I'll become the strongest soon enough. Not just that, I'll become invincible so that no one will even think to pick a fight with me. Hahahaha!"

Those words spoken by his son brought his focus back from his wandering thought.

'You always had that unwavering confidence in you Satoru, but the world is darker than what you have seen. Even in this village, there are people who covets power and would do anything in order to obtain more of it.' Sakumo mused while smiling at his son.

"Then you got to study and train more to achieve that ambition of yours Satoru. A genius who works harder than anyone else will never be surpassed by others." said Sakumo.

"Ugh, you're probably right. Even if I don't like the boring stuff, I still need to put in the effort in doing them to be the best."

"Good, perseverance is important for a shinobi."

Just as they finished talking, they finally arrived to the front of the Ninja Academy. There are quite a lot of parents with their children entering the academy for the admission.

As they were to enter the academy grounds, they met a strange father and son duo in green. Being the polite man he is, Sakumo went and greeted them first.

"Oh, nice to meet you! My son will be attending the academy. I hope those two will get along okay." said Sakumo enthusiastically.

"I'm afraid that will be impossible!" said the father.

"Huh? What a thing to say! Are you one of those monster parents?!" replied Sakumo in surprise.

"You're wrong Dad, this kid failed the academy entrance exam. I hear he can't even use ninjutsu" Satoru truthfully(ruthlessly) answered.

"..."

"Ah...Sorry about that...You were standing in front of the Academy, so I thought..." Sakumo replied while embarrassed.

"Gahaha, ah, that makes perfect sense!!" the father laughingly replied.

"But, I can see the amount of effort he puts into his strong point." Satoru suddenly cuts in.

"!!!"

"!?"

"Hm!?"

"Your hand is bruised from some sort of repetitive training, probably against some wood log. Your body muscle is far more build than what a normal 5 year old supposed to have, definitely the result of constant training. You might not be capable of ninjutsu or genjutsu but if you put your whole effort into taijutsu, you might become one of the strongest by pure taijutsu instead." Satoru calmly analyze the condition of his fellow 5 year old with his Rikugan. It surprised him that someone at his age could have such physique but what surprised him even more is the amount of training one needs to go through to achieve this.

Even his physical training doesn't come close to such level.

While the other three were silenced from his word, he asked the other boy.

"My name is Hatake Satoru, what's yours?"

"!!!"

"M..my name is.. Maito Gai" Gai replied.

"Heh, don't give up. If you can enter the academy as the reserve student, maybe the next few years wouldn't be too boring." Satoru said while smirking.

Gai's father smiled when he heard this. Gai's expression also brighten up. They both raised their thumb and together said.

"THANKS FOR YOUR SUPPORT!!!"

"No problem! Well then, we'll be going first then. Let's go Dad!" Satoru answered.

"Sorry for my earlier words! Keep up the good work and good luck!" Sakumo said while following his son to enter the building.

"You see Gai! There are others who can see and appreciate your hard work, they believed that you can become a great ninja even with only taijutsu. Let's prove yourself to their expectations Gai! This is YOUTH!!!" said Dai.

"YOSH! I'm gonna do everything that I can to prove myself worthy of being accepted to the academy!" Gai replied excitedly.

As the two leaves the Academy, Satoru and Sakumo had their own small talk.

"Well Satoru, you've seen now that there's other who put in more work than you. At his current rate, he might even surpass you in a few years." teased Sakumo.

"Hahaha, that's only if I slow down my progress. Now that I've seen someone like him, I'll only get more determined to grow stronger and faster!" Satoru confidently replies.

"Gai, that boy will make a great rival for you." Sakumo told his son.

"Rival? We'll see if he can catch up." Satoru still smiling while saying that.


Author's Note/Rant :

Phew, I thought writing fanfic would be easy as long as you have a clear concept on how the story goes. Turns out I was very wrong.

So yeah, basically Kakashi is replaced by Satoru in this fic. Sorry for the Kakashi fans who read this fic but I really want to write about this for a while. Some fanfics I've read about this trope usually had Satoru as Kakashi's brother but I think such things will just make it too easy considering Satoru skill set compared to Naruto's bad guys up till the Fourth Shinobi World War. There's also the plot holes or bad writing that turns me off from reading further. So, yeah this fic is completely powered by passion and desire to see a good fanfic about having a Gojo Satoru(at least his power and a bit of his personality) in Naruto Verse. God give me strength to write this through till the end.

Regarding this Satoru's power, yes the usual Blue Red Purple technique will still be incorporated later on as a jutsu similar to how Tsukuyomi, Amaterasu, and Susano'o are connected to the Mangekyou Sharingan. The Endless Void of Satoru in this fic will probably be treated as either a special type genjutsu or something else(haven't really thought about it and it's still kinda far). Oh yes, this Satoru as you can see is completely natural born in Naruto Verse so he got to figure out his true strength by himself later.

There's lots of other things I want to say, but it's better to tell it through the story itself rather than writing it here.

As for the next chapter, I'm probably gonna wait it out a week first before writing it, college totally does not help with my free time to write this fic. Just to see some helpful input first, the less plot hole this fanfic had the better it is. Hopefully I won't have to rewrite this fic in the future after realising how many problems it has.

Please leave your review, critique, and suggestion. To let me know what's to improve upon. Of course some explanation will tremendously cuts down the time I need to figure it out.