The Idea of Using Immortal Arts Chakra to Open the Eight Gates

Kimura Takuya eventually went to the hospital after all.

He wasn't sent there by Ino; he went on his own after finishing his exam and receiving his forehead protector.

This was after he had set a time to study with Neji.

Ino had originally wanted to ask Takuya out for a meal, but she had work at the hospital tonight, so she had to give up on the idea.

A worker's soul, a worker's spirit; even after transmigrating into the ninja world, he remained a worker.

And so, the worker arrived at Konoha Hospital.

"Sister Tomiko, what's for dinner tonight?"

"Oh, Takuya, it's ramen today. I've already set aside your portion."

Kimura Takuya sat down happily and began to eat.

Seeing the forehead protector on his head, Tomiko teased him with a smile.

"Ha, who would have thought the little brat has grown up? You've become a genin capable of standing on your own, though it's a shame you have to start working at the hospital right after graduation. Don't you find it boring?"

Dressed in her nurse's uniform, Tomiko smiled like a blooming flower, a sight that was truly pleasing to the eye.

However, Kimura Takuya didn't linger on the sight, focusing instead on his ramen.

"How could it be? I'm a veteran employee too; I started working at the hospital on the same day as you. Don't you remember?"

"Haha, I did come to the hospital right after I graduated, which is why I asked if you'd be bored."

"Not at all. I quite like medical ninjutsu."

"Speaking of which, with your talent for medical ninjutsu, even if the director took you on as a personal disciple, it wouldn't be a problem. It's a pity the director has been gone for many years; who knows when she'll be able to return."

Tsunade, was it? The founder of Konoha Hospital and the pioneer of Konoha's medical ninjutsu.

The strongest medical ninja and one of the legendary Legendary Sannin.

Tsunade was still busy dodging debts all over the world at this time.

If one wanted to learn medical ninjutsu from Tsunade, it wouldn't be so easy.

Whether she would be willing to teach you was one thing, but just finding her would be a task in itself.

With that kind of time, he might as well practice on his own, and besides, Kimura Takuya's goal was never to become a medical ninja.

Learning medical ninjutsu was merely a cover for his own immortality.

After finishing dinner, Kimura Takuya went to the wards for his night rounds.

Medical ninjutsu was not omnipotent; it was fine for treating external injuries, but it was somewhat inadequate for other types of pathologies.

In a sense, the invention of medical ninjutsu was actually for the sake of war, not for curing illnesses.

In ninja combat, most injuries were external trauma.

That was why medical ninjutsu existed—to accelerate metabolism and promote cell division, thereby rapidly healing wounds.

Other medical knowledge in this world, the kind used to save lives from disease, was actually quite scarce.

If one were to calculate it, it was really only at the level of the Sengoku period in Japan.

The technology in Naruto was also quite baffling; there were radios, electric lights, televisions, and refrigerators, yet when it came to fighting, it was mages with cold weapons taking the stage—there were no thermal weapons at all.

And yet, there were things like "Iron Man" and even laser weapons.

Mecha Naruto and Mecha Kurama were also completely absurd.

Over the years, Kimura Takuya had already filled in quite a bit of basic medical knowledge.

Otherwise, how could he have been recommended for the ninja academy and guaranteed a hospital job upon graduation?

Learning medical ninjutsu alone would only get you by as a male nurse.

But Kimura Takuya had now officially entered Konoha Hospital, starting as a physician's assistant.

Normally, after a few years, once his chakra reserves were sufficient, he could be promoted to a full physician.

Although his current chakra levels were already enough, as mentioned before, his goal was not to be a medical ninja.

After finishing his rounds, Kimura Takuya went to the hospital laboratory.

There was no one around at night, and Kimura Takuya often came here to conduct research; the acting director had specially approved a key for him.

The night's work officially began.

He was dissecting a frog—not a toad from Mount Myōboku.

Just one he had grabbed from the grass on his way over.

Over the years, he had already dissected almost every small animal in Konoha.

At first, it was just out of boredom, wanting to see how the creatures of the ninja world differed from those in his previous life.

He hadn't known until he dissected them, but the results were shocking.

These creatures of the ninja world were generally much stronger than those in his previous life.

The human body was no exception.

This discovery led him to realize that the influence of chakra might be ubiquitous, though it was far more likely to be the influence of natural energy.

Natural energy is a miraculous power that permeates the entire ninja world.

When this power is mixed with chakra in a specific ratio, it becomes Sage Chakra.

Mastering Sage Chakra allows one to activate Sage Mode, turning any ninjutsu released into senjutsu.

Senjutsu possesses greater power and lethality than ordinary ninjutsu.

In truth, this is easy to understand; after all, since the energy being utilized is more potent, the techniques released will naturally be stronger.

However, ordinary technical means are completely incapable of observing natural energy, and even the Byakugan cannot perceive it.

But through comparative dissection experiments, Kimura Takuya began to form some ideas.

It seemed that natural energy was subtly influencing the bodies of animals.

The longer they lived, the more obvious this influence became.

Furthermore, after dissecting thousands of various animals, he discovered something interesting.

Kimura Takuya found that frogs, loaches, and slugs were the three types of animals most significantly affected by natural energy.

This was quite intriguing.

Anyone who has watched Naruto knows.

The existence of the three great holy lands—Mount Myōboku, Ryūchi Cave, and Shikkotsu Forest—corresponds exactly to these three animals.

So, does that mean Ryūchi Cave is actually filled with a bunch of loaches instead of snakes?

Or perhaps the White Snake Sage has loach lineage?

Setting aside the question of the White Snake Sage's lineage for the moment, one must simply consider: why these specific creatures?

After delving into the commonalities of these animals, Takuya discovered that they are all capable of cutaneous respiration.

Yes, that is correct.

Being able to breathe through the skin means that every cell in their body can directly contact the air and participate in the exchange of oxygen and energy.

Therefore, it is possible for the natural energy in the air to accumulate within their cells.

And Sage Chakra is a combination of spiritual energy, physical energy, and natural energy.

The three great sages likely draw upon the natural energy deposited within their cells at the same time they refine chakra and mobilize their physical energy.

Only then do the three combine to form a new type of energy—Sage Chakra.

Moreover, they likely discovered Sage Chakra independently, which is why practicing the senjutsu of different holy lands yields different effects.

Because the Sage Mode of each holy land is, in reality, the one best suited to its own inhabitants.

When humans practice the senjutsu of a particular place, they manifest the characteristics of that place.

Thinking about it this way, Kimura Takuya remembered that humans are also capable of cutaneous respiration.

It is just that the efficiency is extremely low, far lower than that of these three species.

If he could improve his own skin's respiratory ability and increase the natural energy within his cellular tissues, could he not also develop a form of senjutsu that truly belongs to humanity?

If he could instantly activate Sage Mode and then use Sage Chakra to open the Eight Gates, wouldn't he be able to crush the heavens, the earth, and everything in between?

Furthermore, even someone as powerful as the God of Shinobi, Senju Hashirama, who could instantly activate Sage Mode and use it indefinitely, died under mysterious circumstances after his battle with Uchiha Madara.

One must realize that the three great sages have all lived for thousands of years.

This is undoubtedly the result of them mastering their own internal senjutsu.

It is laughable; the secret to immortality that Orochimaru sought in vain was hidden within the bodies of these small animals all along. How fickle fate is.

After Orochimaru performed the Living Corpse Reincarnation for the first time, he had already lost the qualifications to learn senjutsu.

In the parlance of cultivators, cultivation emphasizes a complete spirit and sufficient qi; the spirit is the soul, and the qi is the blood.

Since his Living Corpse Reincarnation damages his soul every time it is used, his soul is incomplete, making it impossible for him to learn senjutsu.