After Orochimaru left, Aoba stepped out of the room and noticed that the door of the adjacent room was slightly ajar, with Karin peeking out.
"It's okay, you don't need to worry. The snake has left."
"Ah, that's great. I'm so scared of snakes. They're just so disgusting."
"Is that so? Actually, I feel the same way."
It was the truth. Orochimaru's snake techniques were indeed a bit unsettling.
"Alright, Karin, come over. I'll check your condition."
"Okay."
Although Aoba wasn't a professional medical ninja, he had learned some medical knowledge while working under Orochimaru. He had considered pursuing a career in medical ninjutsu since it was a safer path.
However, the limitations were too restrictive, and since he was already in this world, he couldn't resist aiming for higher levels of power.
Karin was still young. Although she had been bitten several times, her resilience was strong. After being well-nourished for some time, her body had recovered quickly.
Even the bite marks on her skin were gradually fading.
"Your body is recovering very well. At this rate, in about a week, you'll be fully healed. By then, you can go to school."
"School? I still have to go to school? Aoba, I don't want to go..." Karin instinctively began to whine, but Aoba firmly refused.
"Going to school is necessary. I often need to go on missions and don't have time to teach you. School will help you learn and solidify basic ninja knowledge. Most importantly, you'll get to meet some peers.
Don't worry. Konoha is different from Kusagakure. The students here are quite good. Once you go, you'll make new friends, which will be beneficial for your growth."
In fact, Aoba had another reason he hadn't mentioned. Karin was from the Uzumaki clan, which meant she had basic chakra reactions. Not sending her to school would seem suspicious.
As previously stated, Konoha wasn't absolutely safe. With Danzo lurking around, he needed to stay vigilant.
By sending Karin to school openly, he could dispel any suspicious eyes. Although Yumi knew this reason, Karin was still too young for him to explain it to her.
Compared to Karin, Yumi's condition wasn't as promising.
Despite being well-nourished recently, her condition had stopped deteriorating but had not improved. She wasn't getting worse, but she wasn't recovering either.
Yumi was actually quite young, only a few years older than Aoba—around twenty-four or twenty-five.
According to the Uzumaki clan's constitution, she should have recovered quickly. Her inability to recover indicated that her life source had been severely depleted.
The Kusagakure ninjas didn't treat her as a human and deliberately bit her, leaving her body almost exhausted.
"Sir, you can tell me directly. How long do I have left?"
"I've told you, just call me Aoba. Given your current condition, you probably have about two to three years left."
"That's enough. At least I can spend this last period with Karin."
"There's no need to be so pessimistic. I've mentioned that I have a method to save you, though it requires time and involves some risk."
"I believe in you. When the time comes, let me know. No matter the risk, I'm willing to try."
"I will."
Yumi's situation was very complex. Her life had been overconsumed, not just a simple injury.
Therefore, using Karin's blood in this situation was completely impractical.
Aoba had spent time studying their special constitution. He initially thought that their blood could heal their injuries.
However, he later discovered that this wasn't entirely the case. While their blood contained immense life force, it couldn't account for the rapid healing.
When they were bitten, the life force in their bodies flowed out with the blood and directly into the attacker.
This was the reason for the rapid recovery. But this recovery only addressed external wounds and didn't replenish the life source. Thus, using Yumi's blood in this way was impractical.
This was a very complex issue. Even as a professional, Aoba couldn't completely understand the intricacies.
He speculated that biting might only be a superficial method of utilizing and absorbing life force.
To replenish Yumi's life force, a deeper level of supplementation was necessary, but he didn't have a clue about how to achieve it.
He had decided that if this method didn't work, he would use his own approach—transplanting Hashirama's cells. If successful, it would definitely replenish or even enhance her life force.
A week later, Karin reluctantly went to school, and after completing several missions, Aoba finally managed to secure a long vacation. He then began research work in the basement of his home.
Orochimaru was highly efficient. Within three days, he had sent the sealing jutsu materials and various experimental equipment.
To be honest, Aoba envied Orochimaru's ability to always have money and equipment.
These items would have cost tens of millions or even over a hundred million ryo if he had to buy them himself, but Orochimaru provided them directly.
Aoba set up a basement and converted it into a laboratory to continue his research.
The Hashirama cells had arrived, but another condition had yet to be met, so he would hold off on using them for now.
His current focus was still on Karin.
Karin's constitution was undoubtedly very useful. However, he wasn't like the Kusagakure ninjas who could exploit a little girl as a constant blood supply.
Yet, he was envious of the effects. Aoba's plan was to periodically draw a portion of her life force while ensuring her health remained unaffected, storing it for future use.
The little girl had exceptionally strong life force. Although she couldn't sustain an entire village, drawing a tube of blood each week wouldn't significantly impact her health.
However, this raised a problem. As mentioned before, Karin's life force wasn't just in her blood. It flowed out with the blood.
The released life force was the key to rapid healing. Aoba needed to find a way to seal this released life force and create a restorative potion.
To achieve this, he needed medical techniques combined with sealing jutsu, which was why he requested the sealing jutsu materials from Orochimaru.
Most of his research would require delving deeply, and sealing jutsu was indispensable.