Requirements

While the chief arranged for his addmission to the academy Rei was training in house since he was told the academy session wouldn't start until after a month.

He would regularly control his chakra trying to understand the mysteries of this new energy.

After some time of controlling his chakra realised that he had infact two sources of spiritual chakra the black chakra that belonged to the original Rei and the white chakra that belonged to him.

He could gather the white chakra quite easily but whenever he tried to gather the black chakra it would start going berserk and would start to eat away at his white chakra.

The white chakra inside him was quite miniscule in comparison to the black chakra and wasn't able to endure the spiritual pressure of black chakra making him unable to do anything.

'I still know very little about the chakra as a whole.'

Since he lacked much knowledge he decided to stop touching the black chakra completely for now since he knew with time and training the amount of his white chakra would increase.

As for physical training it was also necessary to increase the physical aspect of chakra.

The more he trained the stronger it would get.

He also realised that the physical limits of body were quite high due to chakra and this limit also increased the more he trained.

So he would also train his body regularly increasing the intensity every day.

...

After month had passed he was told that he was recommended by the clan chief to the academy and today was the day list of those who were selected would be released so he was on his way to the academy with Murakumo.

...

"So this is the ninja academy."

Rei looked at the crowd of children gathered in front of the academy checking their results. Some of them were exited probably those who got admitted others who did not pass had sad and defeated look and some were even crying.

"Yeah don't worry Rei you will definitely be selected since the clan chief personally recommend you."

"Hmm so what is criteria for this selection anyway."

Rei nodded and asked curious how they would judge if these snot nosed brats were really eligible to be a ninja.

"Well there are three requirements for the academy, they should love the village and hope to preserve peace and prosperity, should be able to endure hard work and be healthy in mind and body."

Hearing the requirements a weird look appeared on Rei's face but he did not comment on it.

Rei went up to check his names pushing his way through kids who were checking the list for the nth time hoping it would appear there if they kept doing so.

'Hmmm ...Obito Uchicha ... Kakashi hatake... ah there it is Rei Kurama.'

Having made sure his name was there on the list he told the news to Murakumo who did yes pose in happiness.

"Congrats Rei, lets celebrate your entrance to the academy with some tasty ramen, my treat"

He said while patting Rei back.

"Sure thanks Murakumo" Rei replied in a. happy tone which made Murakumo smile.

On his way out he looked at boy in a green jumper running around the academy ground with a banner on his back with the words

*If I run 500 laps i will be accepted as an alternate.*

'Well someone is persistent, looks like i need to work harder as well' Rei wondered how could they not accept such a wonderful kid to the academy.

He smiled and gave a thumbs up towards the tired kid who smiled in thanks and picked up the pace thinking his hard work was not in vain.