Early the next morning, Hinata came to the cultivation site agreed with Kai, which was a remote grove near the river, which would not be disturbed by people and was not too far from the village.

Hmmm...

Before Hinata entered the forest, there was a sound of breaking wind in the forest.

Immediately afterwards, the two figures rushed out of the forest one after the other, and the fierce fight was together, the whistling of the fists, and the muffled sound of the fists and feet intersecting, were endless for a while.

"Heh, these two guys are really idle!"

After chuckling, Hinata jumped onto a big tree and sat down leisurely.

It wasn't anyone else who fought in the forest, it was Kakashi and Kai, and the two of them may have arrived first, so they waited for the Hyuga mirror to have a daily discussion.

The Hinata mirror on the tree took this opportunity to carefully observe the two people in the discussion.

Both of them have excellent physical skills, and their speed is also extremely fast, when they shuttle through the forest, they look like two ghosts dragging long afterimages, if they were ordinary people, they wouldn't be able to see the details of their fight at all, but this is difficult to have the reincarnation eye of the Hyuga mirror.

Holding his chin with one hand, Hinata Mirror observed and commented: "Kai's moves are really getting more and more powerful!" ”

The ninja of the steel fist stream, if they want to improve their strength, there is actually no way to take advantage of it, and they can only improve their speed and strength through hard training day after day.

Therefore, compared to ninjutsu-type ninjas, the strength of steel fist flow ninjas has improved more slowly.

But this does not mean that Steel Fist has no future, on the contrary, as long as you can endure loneliness and hardship, the upper limit of Steel Fist ninjas is far higher than that of ordinary ninjutsu ninjas.

Kai is a good example, in his contemporaries, except for a very few geniuses like Kakashi, the vast majority of them have clearly begun to slow down in their twenties, and some have even begun to stand still.

Kai is different, he was inconspicuous when he was in the ninja school, and was left behind by many contemporaries, but as time went by, his strength was not in a hurry, and he steadily improved little by little, but one by one he overtook his contemporaries who were better than him before, and unconsciously, he grew into a powerful shinobi who felt reassuring.

Turning his attention to Kakashi again, Hinata observed it for a while and whispered, "Hey, what's wrong with this guy Kakashi..."

In the middle of his sentence, he suddenly stopped talking, because he realized that he couldn't think of a word to accurately describe Kakashi's current state, and Kakashi now gave him a very strange feeling, as if he was at some critical point, or rather, in some kind of critical transformation.

At this time, after sensing the arrival of the Hyuga mirror, the two people in the discussion stopped in unison.

Jumping down from the tree, Hinata walked over and said hello: "Hey, you two came really early!" ”

Kai showed a mouthful of big white teeth and said with a smile: "Mirror, sweating in the morning sun is what youth should look like!" ”

Kakashi didn't speak, just nodded towards Hinata.

As he got closer, Hinata felt more and more that Kakashi's body had a sharp edge, and the whole person seemed to be like a sharp blade glowing with cold light.

Hinata couldn't help but ask, "Kakashi, are you okay?" ”

Kakashi shook his head, "I'm fine. ”

He actually knows what Hinata is referring to, and he also understands that in order to gain stronger strength during this time, both his personality and temperament have changed a lot, but he has no regrets, because he needs strength to correct his best friend who has gone astray.

Hinata smiled: "You look so energetic, I'm really not used to it!" ”

Kai also chimed in: "Yes, you were always late for previous dates, but I didn't expect to come earlier than me today, which really scared me!" ”

Kakashi didn't have the heart to joke, and seeing that everyone had already arrived, he urged, "Let's start." ”

After the three of them came to the woods, Kai put away his smile and said with a serious face: "'Eight Gate Dunjia' is not so much a forbidden technique, a technique, but a habit, a physical habit!" ”

Starting from the first gate 'Open the Door' at the center of his eyebrows, Kai pointed to the human body acupuncture points corresponding to the Eight Gates in turn, and finally stopped his hand at the heart, which is the position of the Eighth Gate 'Death Gate', and said: "These eight gates are actually the eight hubs that protect the meridians of the human body, and the meaning of their existence is to restrict ninjas from over-refining chakra, so as not to cause irreversible damage to the body." ”

Hinata asked, "So the key to cultivating the 'Eight Gates Dunjia' is not just to knock on the eight hubs in the meridians, but to get the body used to opening the overload state of these hubs?" ”

Kakashi also asked, "The order of these eight doors should also be arranged according to the difficulty of the body's adaptation, right?" ”

Both Hinata and Kakashi are excellent ninjas with both theory and actual combat, so the two of them got a lot of information from Kai's introduction to the 'Eight Gate Dunjia'.

Listening to the questions of the two people in front of him, Kai, who was going to introduce the 'Eight Gate Dunjia' in detail, was choked up, opened his mouth, and didn't know what to say for a long time.

Hinata asked, "What's wrong, we misunderstood?" ”

"No..."Kai, who came to his senses, hurriedly shook his head and said, "You two understand very correctly, the core of the 'Eight Gate Dunjia' is to get the body used to the state of opening these hubs. However, the body can only adapt to the first seven gates, and the eighth gate, the 'Death Gate', located in the heart area, is a forbidden door that must not be easily opened! ”

Kakashi asked, "What happens if the 'Door to Death' is opened?" ”

Kai said with a solemn face: "Once the 'Death Gate' is opened, the chakra will increase tenfold or even dozens of times in a short period of time, allowing an ordinary shinobi to instantly gain more strength than the Hokage, but the consequence is death!" Because no matter what, normal people can't bear the huge burden after opening the 'Door of Death', so death is an inevitable result, which is why the eighth gate is called the 'Forbidden Gate'! ”

After learning about the effect of opening the 'Door of Death', and the cost, Kakashi did not feel palpitations like a normal person, but fell into deep thought, as if he was seriously considering the occasion to open this 'forbidden door'.

Hinata was also thinking.

In the original time and space, Kai, who opened the 'Door of Death', did not really die, because he was treated by Naruto, and the power on Naruto's body came from the Six Immortals, so as long as the Hyuga Mirror can achieve the 'Blood Relay Snar' in the 'Blood Relay Fusion Ceremony' and make his life level get a qualitative change, then even if he opens this 'Forbidden Door' during the ceremony, he will not die!