Inside the laboratory!
A mouse with a severed hind leg had fully regenerated by now. Other than a bit of missing fur, it was indistinguishable from its previous intact state.
Although Uchiha Mei couldn't see, her other senses were still sharp, and she could tell that the mouse in her hands hadn't been swapped by Akira Sato.
"This… how is this even possible?"
At this moment, she no longer wore the hopeless, defeated look she had before. She kept running her fingers over the mouse, murmuring to herself.
For a ninja like her, touching a mouse — even a snake — didn't faze her in the slightest.
"Why would it be impossible?"
"You're too narrow-minded."
"There's no such thing as impossible."
Akira Sato spoke confidently.
The results were right in front of her — how could he not hold the upper hand?
Besides, he didn't think this achievement was particularly astonishing.
In the future, that backstabbing Obito would lose half his body and still be saved by the master manipulator Madara using White Zetsu. Not to mention Orochimaru's cloning technology… All of those were far more advanced than what Akira had just pulled off.
They were using techniques, whereas Akira's breakthrough was purely thanks to the cheat-like properties of his unique blood.
Without the special properties in his blood, creating something like this "Regeneration Serum" would've been impossible.
The Regeneration Serum!
No matter who used it, this serum would give them a "new life," making the name exceptionally fitting.
"When can we start?"
Uchiha Mei turned eagerly toward him.
The time she'd spent blind (it had already been days since her injury, as they'd secretly sought treatment before today) had been pure torment. Now, she couldn't bear to wait even one second longer.
"Not yet," Akira shook his head, explaining, "We're still only at the animal testing stage. We don't know if there are side effects, and most importantly, we have to figure out the correct dosage."
Hearing this, Uchiha Mei calmed down somewhat and asked,
"Is there anything I can help with?"
With such a successful example in front of her, she no longer worried about permanently losing her sight, so her patience quickly returned.
After all, patience was a core trait for any ninja.
"I need you to help me place a commission through the bounty exchange to find a certain summoning scroll, gather these materials…"
Akira listed out his needs.
"Alright!"
Uchiha Mei didn't hesitate in the slightest.
As the granddaughter of the previous clan head, her influence was far greater than one might imagine.
Before, she had been consumed by despair, which was why she hadn't taken action — but when she really wanted to get things done, neither manpower nor funding was an issue.
Before long —
A specially commissioned bounty was posted at the underground exchange.
The Bounty Exchange!
It was a mediator network spread across the entire shinobi world, where literally any kind of mission could be posted, without restriction.
A 30 million ryo bounty!
This price was already astonishing.
For comparison, the bounty on the heads of some small village leaders probably wasn't even that high.
In a hidden exchange station in the Land of Fields —
Thud!
A corpse was thrown onto the counter.
Hidden entirely under a cloak, a figure with eyes like small green beads silently counted the coins in his hands.
"Kakuzu-sama, I wonder if you might be interested in a 30 million ryo job?"
The exchange's manager carefully inquired from behind the counter.
"30 million ryo?"
Kakuzu, mid-count, instantly lost interest in the money he was holding.
After working hard for an entire month to hunt down the Jonin whose body now lay at his feet, he'd earned just 2 million ryo — and now, a single mission offered 30 million? How could that not grab his attention?
"That's right. The client specifically requested you…"
The manager didn't understand why anyone would dare commission someone as dangerous as Kakuzu — but that wasn't his concern. His only job was to handle the transaction.
"I'll take the job!"
Kakuzu didn't fear difficult missions. His only fear was missions that didn't pay enough.
With a price this high, even assassinating a Kage from one of the five great shinobi villages wouldn't be out of the question.
Thud!
Upon hearing Kakuzu accept, the manager immediately performed a summoning technique to retrieve the mission scroll.
Taking the sealed scroll, Kakuzu carefully opened it and reviewed the mission details.
The task was surprisingly simple:
He was to go to Drowning Swamp and retrieve a summoning scroll.
The client had provided some intel, mainly that the scroll was guarded by a powerful giant lizard with specialized abilities…
Armed with this information, Kakuzu felt confident he could complete the mission.
The only slightly annoying part was that after completing the task, he wouldn't deliver the item directly to the client, but rather to a small merchant caravan.
Still, no problem — the full payment had already been deposited through the exchange, so there was no risk of getting stiffed.
After reading through the scroll and tucking it safely into his cloak, Kakuzu carefully packed away his freshly counted money, then slowly exited the underground exchange.
Meanwhile!
Akira Sato was busier than ever.
Not only did he have to focus on his personal training, but he also had to develop new techniques, research the serum…
He practically wished he could split himself into several copies just to keep up.
Oh right!
There was a jutsu that could achieve that —
Shadow Clone Technique!
This B-rank jutsu was practically a must-have cheat skill for any isekai protagonist.
Although Uchiha Mei could potentially acquire this technique, she couldn't pass it on to Akira.
Not only because of village and clan restrictions, but also because of the learning difficulty.
At minimum, it required a Jonin-level shinobi to master.
Even though Akira's combat ability had skyrocketed — thanks largely to the presence of Taiichi — and he was much stronger than an ordinary Chunin, purely by his own strength, he was still far from Jonin level.
In the anime, Jonin often seemed like background characters, overshadowed by Kage-tier and even Six Paths-level figures.
But in the real shinobi world, you quickly realized how unrealistic that portrayal was.
Even the most minor Jonin was considered a major figure in any shinobi village.
In the entire Hidden Leaf Village, with over ten thousand active ninjas, there were fewer than two hundred Jonin — which showed just how rare and difficult they were to become.
So, for a freshly graduated Genin like Akira, dreaming of mastering Jonin-level techniques was just wishful thinking.
Of course —
If he were a Nine-Tails Jinchuriki with Uzumaki blood, that might be a different story.
(Naruto: Why don't you just call me out by name already?!)
Unfortunately, he wasn't — so instead, Akira could only act as a "time management master," carefully planning out every part of his day and working himself to the bone.
His dream was to live a carefree life —
But right now, he couldn't even lie down to rest; instead, he was grinding like a corporate 007, working nonstop, with bitterness piling up in his heart.
All thanks to Danzo!
The one bright spot was that his progress in developing new techniques was advancing by leaps and bounds.
Though he was still far from the level of overpowered protagonists, at least he could now reasonably be called a "genius."
With his creativity and solid knowledge foundation, plus technical guidance from Minato Namikaze, things were progressing smoothly.
Once he had his own custom jutsu, his strength would soar.
Plus, he had already extracted several doses of the Regeneration Serum — once human trials were complete, it would be ready for official use.
As for how to test it on humans?
Akira certainly wasn't going to use himself — but with Uchiha Mei arranging things, that was a different matter.
Today, it was finally time for the experiments.
He arrived at a completely unexpected experimental site.
(End of Chapter)