Ryo’s talent with lightning release was nowhere close to his talent with water release. If Chidori was a water Jutsu he would have mastered it much earlier
After training for a dozen days in the forests of Konoha, he was able to start Chidori. But the duration that he could’ve maintained it for was nowhere close to Kakashi, he couldn’t form it then attack with it.
While in the original manga, Chidori was described as a technique developed for assassination, Ryo didn’t have that purpose for it.
In his vision, the purpose of studying Chidori, Raikiri, Chidori Senbon and Chidori Nagachi is to grasp shape transforming thunder release techniques.
He couldn’t maintain Chidori for enough time for it to be effective. Through experimentation, he found out the problem was chakra related. He has been focusing maintaining the stability of the jutsu but has ignored the chakra input.
Indeed, when he made sure his palm was fed with a continuous flow of chakra, the electric current created by his hand became much more stable. As the jutsu came to life it sounded like the singing of a 1000 birds, getting all the real ones in the forest startled.
Ryo activated his sharingan, and rushed to a distant stone! ‘’AAHH” The stone was easily broken. Ryo’s attempts to use Chidori finally became successful.
In the spirit of being thankful and giving back to the giants he’s building his success on, he decided to pass this technique on to its original inventor.
“Kakashi, since you’ll be graduating next year, I will give you a graduation gift in advance.”
“What gift?” Children love to receive gifts and Kakashi was no exception. Ryo invited him on his own for this. He was full of hope for this gift.
“My own developed A-grade ninjutsu, Chidori.”
“You, developed yourself, an A-grade Jutsu?” Kakashi’s dead fish eyes got wide open. Ryo felt kinda bad about getting all cheeky with something that is not his own.
“Kakashi, let’s get started.”
Kakashi’s talent in with thunder was far superior to that of Ryo, he learned Chidori in just three days. But his 4 year old body only gave him enough chakra to pull it off just once at a time.
In the manga, Kakashi developed the Chidori after graduating. Now he has it as a 4 year old. When he Graduates, he should be able to make great things with this technique.
Later on, the two went on to discuss the many possible variants of this technique, and Kakashi became more and more impressed with Ryo.
He returned home to receive his daily training for his father. Hatake Sakumo was very strict with his son. After the basic practice was completed, they started fight training.
The Hatake family’s knife methods are not simple basic knife play, but they are close to a body extension technique. Their special Taijutsu relies on using lightning release to stimulate the nerves and cell, thus greatly increasing their speed, their inherited Short Knife is made by chakra-phile metal, thus helping them integrating the body and blade into one.
As usual, Kakashi wasn’t doing much against his father, who was able to hit him easily. Of course, the strike was greatly weakened by Sakumo to an extent that prevents it from inflicting serious damage.
But when pushed by the strike, Kakashi didn’t rush back towards his father, instead he started forming hand seals : “[Chidori]!” Kakashi had his new attack in hand, and rushed towards his father.
“This jutsu !” Sakumo’s face that’s been calm all along suddenly turn serious, he saw a great potential of penetration and paralysis in the attack, but Kakashi didn’t master this technique yet, so his high speed thrust limits his dynamic vision range. Once the opponent makes a move, Kakashi shouldn’t be able to follow. Sakumo exploited this weakness to evade to the right and grab his son’s right hand.
“Kakashi, what is this technique?”
“This is a new ninjutsu technique [Chidori] that Ryo developed. He said it was A-grade ninjutsu. It is a graduation gift that was given to me in advance.”
Ryo has developed a level A Ninjutsu by himself?! And is a grade A technique not that important to him as he gave it as a present?
“Kakashi, you should not use this technique for the time being.”
“Why?”
“This technique is incomplete technique for you. Just when you were thrusting at a high speed, you couldn’t see how I moved in the end.”
Kakashi looked back on that scene and just nodded.
“There is a limit to the person’s dynamic vision. When you use this technique, your eyes cannot keep up with your speed. You cannot find the enemy’s movement. Therefore, this technique should not be used until your problem of dynamic vision is resolved.”
Kakashi knew that his father was right and nodded in agreement.
“What about Ryo? Should we tell him to.”
“There is no need, each of you will have his own solutions to his own problems. You continue to practice! Tomorrow bring me Ryo. I have something to say to him.” Afterwards, Sakumo returned to the inner room and left Kakashi with a blank face.
The next day, after school, Ryo went with Kakashi to his place. They went right into the inner room where Sakumo waited for them
“Father!”
“Sakumo san!”
“Kakashi, you must go out first. I have something to say to Ryo.”
Although Kakashi did not want to, he still had to listen to what his father said, so he went out.
“Ryo, the last time you saved my life, and this time you are also teaching Kakashi [Chidori]. Now, I want to give you something. Here are some of my studies on Ninjutsu. I know you are learning about the attributes of Lightning release’s shape transformations, then you know the principle of these techniques?”
Ryo shook his head, Sakumo understood. Then he went on to say:
“The 1st step of a shape transformation involving Jutsu is gathering chakra, and the second step is to give it it’s attributes through hand seals. You need to provide what you will shape transform later. That’s how the different generations of Raykages did it, the thunder Chakra mode was to them a physical exercise.”
Sakumo’s words made it clear to Ryo that he was going about it the wrong way all along. Unlike other jutsu, Thunder Chakra mode is a close to Taijutsu endurance training.
Sakumo gave Ryo the notebook with his research on the matter. He returned home and could not wait to open it.
In it, the lightning techniques were described in detail. The Hatake family based their techniques on lighting release, and they developed it well over generations.
With Sakumo’s notebook, Ryo has a new path to follow when it comes to the development of Chidori and the training of his body.
The next day in the Konoha Forest, Ryo started practicing in a new way.