Early the next morning, Kagami arrived at the training ground he had agreed upon with Guy.
It was a secluded grove near a river, far enough from the village to avoid disturbances, yet not so far that it was inconvenient to reach.
Whoosh, whoosh...
Before Kagami could even enter the grove, a series of sharp sounds from the air being torn apart reached his ears.
Immediately afterward, two figures shot out of the woods, one chasing the other, and began exchanging fierce blows. The whistling of their fists and the dull thuds of their punches and kicks colliding echoed incessantly through the grove.
"Heh, these two really can’t sit still!"
With a soft chuckle, Kagami leaped onto a large tree and leisurely settled down on one of its branches.
The two people fighting in the grove were none other than Kakashi and Guy.
Apparently, they had arrived a little earlier and decided to engage in their usual sparring session while waiting for Kagami.
Taking advantage of the opportunity, Kagami carefully observed the two from his perch in the tree.
Both possessed exceptional taijutsu skills and astonishing speed. As they darted through the grove, they resembled two ghosts trailing long afterimages behind them.
An ordinary person would have been completely incapable of following the details of their exchanges, but this posed no difficulty for Kagami, who possessed the Tenseigan.
Resting his chin on one hand, Kagami watched their sparring match and commented to himself.
"Guy’s techniques are getting sharper and sharper!"
For shinobi who practiced the Strong Fist style, there were no real shortcuts to improving their strength. They could only increase their speed and power through relentless training, day after day.
Consequently, compared to ninjutsu-oriented shinobi, practitioners of the Strong Fist style tended to improve at a relatively slower pace.
However, that didn’t mean the Strong Fist style had no future. Quite the opposite. As long as one could endure the monotony and withstand the hardships, the upper limit of a Strong Fist practitioner was far higher than that of an ordinary ninjutsu-oriented shinobi.
Guy was a perfect example.
Among the shinobi of his generation, apart from a handful of geniuses like Kakashi, most had begun to experience a noticeable slowdown in their growth by their early twenties. Some had even reached a point where their strength had completely stagnated.
Guy, however, was different.
During his time at the Ninja Academy, he had been rather unremarkable, falling far behind many of his classmates.
Yet as time passed, his strength continued to improve steadily, little by little, without any signs of slowing down. Eventually, he surpassed his once-superior classmates one after another and, almost without anyone noticing, grew into a powerful jonin whose very presence inspired confidence.
Shifting his attention back to Kakashi, Kagami observed him for a while before muttering, "Huh? What’s going on with Kakashi...?"
He suddenly trailed off halfway through his sentence.
For a moment, he couldn’t think of an appropriate word to describe Kakashi’s current state.
There was something extremely peculiar about the feeling Kakashi gave him. It was as though he were standing at some critical threshold, or perhaps undergoing a crucial transformation.
Just then, having noticed Kagami’s arrival, the two sparring shinobi stopped almost simultaneously.
Leaping down from the tree, Kagami walked over and greeted them.
"Hey, you two sure got here early!"
Guy flashed his dazzling white teeth and grinned.
"Kagami! Working up a sweat beneath the morning sun! Now THAT’S what youth is all about!"
Kakashi said nothing, merely nodding at Kagami.
As Kagami drew closer, the sharp, intimidating aura surrounding Kakashi became even more apparent.
His entire being seemed like a keen blade, its cold edge gleaming with an unmistakable sharpness.
Unable to suppress his curiosity, Kagami asked, "Kakashi, are you all right?"
Kakashi shook his head.
"I’m fine."
In truth, he understood exactly what Kagami was referring to.
He was well aware that his relentless pursuit of greater power during this period had brought about considerable changes in both his personality and his demeanor.
But he had no regrets.
Because he needed that power to bring his closest friend back from the path he had strayed onto.
Kagami smiled. "I’m really not used to seeing you so fired up!"
Guy chimed in, "Exactly! You always used to show up late for our sparring sessions, but today you actually arrived even earlier than me! You really gave me quite a shock!"
Kakashi, however, wasn’t in the mood for joking around. Seeing that everyone had arrived, he urged, "Let’s get started."
After the three entered the grove, Guy put away his smile and adopted a serious expression.
"Rather than calling the Eight Gates a forbidden technique or a special skill, it would be more accurate to call it a habit—a habit developed by the body!"
Starting with the First Gate, the Gate of Opening, located near the forehead, Guy pointed out the corresponding locations of all eight gates on the human body, one after another.
Finally, his hand came to rest over his heart, the location of the Eighth Gate, the Gate of Death.
"These eight gates are actually eight crucial control points that protect the body’s chakra pathway system. Their purpose is to prevent shinobi from extracting excessive amounts of chakra and causing potentially irreversible damage to their bodies."
Kagami asked, "So the key to mastering the Eight Gates isn’t simply opening those eight control points in the chakra pathway system, but rather conditioning the body to withstand the strain of operating in that overloaded state?"
Kakashi also asked, "I assume the order of the eight gates is determined by how difficult it is for the body to adapt to each one?"
Both Kagami and Kakashi were exceptional shinobi who excelled in theory as well as actual combat. Consequently, they had already gleaned a great deal of information from Guy’s brief introduction to the Eight Gates.
Hearing the questions from the two men standing before him, Guy, who had originally been preparing to give them a detailed explanation of the technique, was momentarily stumped.
He opened his mouth, but for quite some time, he couldn’t think of anything to say.
Kagami asked, "What’s wrong? Did we misunderstand something?"
"N-No..."
Finally recovering from his surprise, Guy hurriedly shook his head.
"You two understood it perfectly! The essence of the Eight Gates is indeed to condition the body to become accustomed to having those control points opened. However, the body can only adapt to the first seven gates. The Eighth Gate, the Gate of Death, located near the heart, is a forbidden gate that must never be opened lightly!"
Kakashi asked, "What happens if you open the Gate of Death?"
Guy said with a solemn expression, "Once the Gate of Death is opened, your chakra will increase tenfold, or even several dozen times, for a short period. It can instantly grant an ordinary jonin power surpassing that of a Hokage!
"But the price is death!
"No matter what, an ordinary human body simply cannot withstand the tremendous strain caused by opening the Gate of Death. Death is therefore inevitable. That’s precisely why the Eighth Gate is known as the Forbidden Gate!"
After learning about both the power granted by opening the Gate of Death and the price that came with it, Kakashi didn’t react with the fear that an ordinary person would have felt.
Instead, he fell into deep thought, seemingly giving serious consideration to the circumstances under which he might open this Forbidden Gate.
Kagami was also lost in thought.
In the original timeline, Guy hadn’t actually died after opening the Gate of Death, precisely because Naruto had saved him.
And the power Naruto had used to save him had come from the Sage of Six Paths.
Therefore, as long as Kagami could achieve Kekkei Mora through the Bloodline Fusion Ritual and bring about a qualitative transformation in his own level of existence, he wouldn’t die even if he opened this Forbidden Gate during the ritual!