Special Research

After Orochimaru left, Aoba stepped out of the room. Through the crack of the next room's door, he saw little Karin peeking out.

"All right, don't worry. The snake is gone."

"Ah, that's great. I'm terrified of snakes. They're so disgusting."

"Really? I feel the same way, actually."

That was the truth. Orochimaru's snake-based ninjutsu really did make him physically uncomfortable.

"All right, Karin, come over. Let me examine you."

"Okay."

Although Aoba was not a professional medical ninja, he had studied such knowledge while serving under Orochimaru. He had once considered taking the Medical Ninjutsu route, since it was safer.

But its ceiling was too low. Besides, now that he had come to this world, how could he not pursue greater power?

Karin was still young. Although she had been bitten many times, her foundation was strong. After being well fed and cared for during this period, her body had recovered rapidly.

Even the bite marks on her body had begun to fade away.

"Your body is recovering very well. At this rate, you'll be completely fine in another week. Then you can go to school."

"School? I still have to go to school? Brother Aoba, I don't want to..." Karin instinctively began to act spoiled, but Aoba firmly refused her.

"You have to go to school. I often need to go on missions, so I don't have time to teach you. School will let you learn and reinforce the basic knowledge of a ninja. Most importantly, it will allow you to meet some companions.

Don't worry. Konoha is different from Kusagakure. The students here are pretty good. Once you go, you'll be able to make new friends. That will be good for your growth."

There was another reason Aoba did not mention. Karin was a member of the Uzumaki clan, and she also had basic chakra reactions within her body. If he did not send her to school, it would be a little too suspicious.

As he had said before, Konoha was not absolutely safe either. With Pot Kage Danzo around, he needed to remain cautious at all times.

Letting Karin attend school openly would instead dispel those prying eyes. Yumi knew this reason, but Karin was still too young, so Aoba generally did not explain it to her.

Compared to Karin, Yumi's condition was far less optimistic.

Although her body had stopped deteriorating after this period of care, that was all. It had not worsened, but neither had it recovered.

Yumi was not actually very old. She was only a few years older than Aoba, around twenty-four or twenty-five.

Given the Uzumaki clan's constitution, she should have recovered quickly. Her inability to recover now meant that too much of her life essence had been depleted.

Those Grass Ninja had not treated her like a person. They had even deliberately bitten her hard, leaving her body nearly drained dry.

"Sir, can you tell me directly? How much longer can I live?"

"I told you, just call me Aoba. Given your current condition, you have about two to three years left."

"That's already enough. At least I can still stay with Karin through these final days."

"You don't need to be so pessimistic. I told you, I have a way to save you. It just requires time, and there is a certain amount of risk."

"I believe you. When the time comes, tell me. No matter how great the risk is, I'm willing to try."

"I will."

Yumi's condition was actually very complicated. Her life essence had been excessively depleted; this was not an ordinary injury.

So having her bite Karin was completely unworkable.

During this period, Aoba had carefully studied the special constitutions of both of them. At first, he had thought it was their blood that could heal injuries.

But later, he discovered that was not the case. At least, not entirely. Their blood did contain immense vitality, but blood alone could not work so quickly.

After all, once blood entered the body, it needed to be absorbed before the vitality within it could be absorbed as well.

The actual situation was that the instant their bodies were bitten, the vitality within them flowed out with their blood and directly entered the body of the one biting them.

Only then could it produce that rapid healing effect.

But this healing could only restore external injuries. It could not replenish the other person's life essence. Therefore, having Yumi bite Karin was not a viable path.

This was an extremely complicated subject. Even as a professional, Aoba could not completely grasp its mysteries in such a short time.

He deduced that biting someone was likely only a superficial application and absorption of vitality.

To replenish Yumi's life essence, he would likely need to restore it on a deeper level. But for the time being, he still had no idea how to do that.

Aoba had already decided that if this path did not work, he would use his own method and transplant Hashirama Cells. If it succeeded, it would definitely replenish and even strengthen her vitality.

A week later, Aoba sent Karin off to school despite her reluctance.

After going on several missions in succession, Aoba finally managed to apply for a long leave. Then he began his research in the basement of his home.

Orochimaru was highly efficient. Three days later, the materials on Sealing Jutsu and various experimental instruments were delivered.

Honestly, Aoba greatly envied Orochimaru's ability to never lack money or equipment.

If Aoba had bought those things himself, they would have cost at least tens of millions, perhaps even over a hundred million ryo. Yet Orochimaru had simply given them to him.

Afterward, Aoba set up a basement beneath his home and converted it into a laboratory, beginning to advance his research.

The Hashirama Cells had already arrived. But another condition had yet to be met, so he would not touch them for now.

His current subject was still Karin.

Karin's constitution was undoubtedly extremely practical. But Aoba was not a pervert like the Grass Ninja. He could not bring a little girl around with him and use her as a blood bag whenever he wanted.

But he truly coveted this effect. So Aoba's idea was to extract a portion of Karin's vitality at regular intervals, store it without affecting her health, and keep it for emergencies.

The little girl's vitality was exceptionally vigorous. She could not support an entire Kusagakure as a blood bag, of course, but drawing one vial of blood from her each week would basically have no effect on her.

But this involved the issue mentioned earlier. Karin's vitality was not contained solely within her blood. Rather, it overflowed along with her blood.

And that overflowing vitality was the source of the rapid healing effect. What Aoba needed to do was find a way to seal away that overflowing vitality and turn it into a Recovery Potion.

To accomplish that, he would need to combine medical methods with Sealing Jutsu. That was also why he had asked Orochimaru for materials on Sealing Jutsu.

For most of his research, if he wanted to delve deeper, Sealing Jutsu would be indispensable.