Soon, carrying three C-rank genjutsu scrolls, Chiba Shun led the three children away from the mission office.
Once he returned to the Ninja Academy, life settled back into its usual rhythm. He spent his days dealing with academy matters, filling the gaps in Aoki Yuu's plans where he could, and devoting the rest of his time to training.
Chiba Shun's chakra reserves had grown to a respectable level by now. He decided that from this point on, half of the chakra he had once reserved for Earth Release training would be diverted into genjutsu practice.
Genjutsu was completely different from the five elemental ninjutsu.
Learning elemental ninjutsu was relatively straightforward. Once a ninja grasped chakra nature transformation and shape transformation, they could begin experimenting.
Genjutsu, however, was another matter entirely.
Besides understanding its theory, one also needed Yin-attribute chakra to cast it. To learn genjutsu was, in essence, to begin learning how to use Yin Release.
The five elemental transformations had at least some established theory in Kumogakure. Yin Release did not.
The Hidden Cloud had genjutsu users, certainly, but most of them relied on talent and instinct. There was no complete system for teaching the next generation how to cultivate Yin-attribute chakra from the ground up.
Konoha had provided some copied materials, but whether those were complete or intentionally misleading remained to be seen.
Because of that, getting started was far harder than it had been when he first learned Earth Release: Earth Flow Wall.
He began by studying the first C-rank genjutsu on the scroll.
Its effect was simple: it pushed the target's consciousness into a deep sleep, leaving them utterly helpless. It was clean, direct, and dangerous in the hands of someone who could use it properly.
After carefully reading the notes attached to it, Chiba Shun began to think.
This technique itself wasn't that complicated. In theory, if he could just complete Yin-attribute chakra transformation successfully, then performing it should be possible.
As for Yin Release itself… in plain terms, it was the use of soul power.
After reading through the half-true, half-false theories Konoha had handed over, Chiba Shun began sorting through everything he remembered from the original story.
Genjutsu. The Yamanaka clan's Mind Transfer Technique. The Nara clan's Shadow Imitation and Shadow Neck Binding techniques. Dan Kato's Spirit Transformation Technique.
Then there was Kaguya's creation of Black Zetsu, and the way the Sage of Six Paths had allowed souls to exist apart from flesh.
There were also the dōjutsu, especially the Sharingan. Those endlessly shifting eye techniques, in his judgment, should all belong to the domain of Yin Release.
They looked different on the surface, but at their core, they all seemed to share one essence: the use of spiritual power.
Then, all at once, something clicked.
Chiba Shun returned to his room and took out another scroll.
It was the scroll Hyuga Akira had written for him back then, containing the training methods and insights behind the Byakugan and Gentle Fist.
The Sharingan was tied to Yin Release. The Byakugan, in a different way, was probably the same.
Akira's notes focused on the eyes, but hidden beneath that was still a structure connected to spiritual perception.
For several days, Chiba Shun buried himself in theory, making preparations before even attempting his first cast.
Only after those days passed did he finally feel that he had caught hold of a thread.
So he began testing it.
Half a day later, he finally had the sense that he had succeeded.
His spiritual power had moved.
Which meant Yin-attribute chakra transformation had been completed.
But testing genjutsu required targets, and Chiba Shun had no intention of experimenting on students from the Ninja Academy. He didn't yet know how dangerous failure might be.
So instead, he went after animals in the village.
Perhaps because beasts had weaker minds than humans, his first test succeeded almost immediately. A wild boar that had been struggling violently a moment earlier slumped into a deep sleep after one attempt.
He tried again several times after that, and each success made him more certain.
It wasn't just that he had learned a C-rank genjutsu.
It was that his aptitude in this field seemed better than he had expected.
He could tell his limit hadn't been reached yet.
That meant his Yin Release talent was likely sufficient to support more advanced genjutsu.
Encouraged, Chiba Shun spent the next few days learning the other two C-rank illusions.
Genjutsu was much harder to grasp than elemental ninjutsu of the same rank, and progress came slowly. Even so, after learning all three C-rank techniques, he confirmed that he still had room to grow.
So he made up his mind, gritted his teeth, and went back to the mission office.
He bought every remaining C-rank and B-rank genjutsu the village possessed.
Including the three he had already purchased, the total cost came to 850,000 ryō.
After that, only 50,000 remained in his pocket.
At that point, even Chiba Shun couldn't help thinking that he would probably have to borrow money again soon.
Still, he forced himself not to dwell on that and continued training.
C-rank genjutsu proved manageable. For Chiba Shun, learning one now only took a few days on average.
And the pace quickened the more he learned.
Counting the time spent on theory and his first three techniques, he needed only a month and a half to finish all of them.
Of course, "learned" did not mean "combat-ready."
Each of those C-rank genjutsu still required more than ten hand seals. In a real battle, that was far too slow.
Then came the B-rank genjutsu.
The difficulty jumped sharply.
Almost all B-rank illusions required the caster to construct a false scene—a believable illusion world the target would accept without noticing the lie.
And that false world wasn't built solely by the caster. It depended, in part, on stimulating vivid images within the victim's own mind.
That made things much harder.
At first, Chiba Shun tried continuing his practice on animals, but the result was awkward and useless. Those beasts simply lacked the intelligence required to form coherent illusion scenes.
That was a major obstacle.
After thinking it over, Chiba Shun went to Yozuki Ai for help and asked to be taken to Kumogakure's prison so he could train using prisoners instead.
Yozuki Ai did not refuse.
He led Chiba Shun directly to the prison outside the village.
Kumogakure's prison was not located inside the village at all. It stood on the outskirts, equipped with its own barrier system and independent defenses.
If enemy prisoners were captured on missions, they were brought there immediately. No one wanted the risk of bringing them into the heart of the village.
Once they entered, an elite jōnin received them.
He agreed to Chiba Shun's request without much trouble, though he added one condition.
If Chiba Shun later mastered high-level genjutsu, he would have to help interrogate the prisoners being held there.
Chiba Shun had no reason to refuse. That would also serve as practical training.
After making the introduction, Yozuki Ai left.
The prison's commander, Nishida Yuichi, watched him go, then turned back to Chiba Shun with a smile.
"You're Chiba Shun, the one who ran around the village with a dozen explosive tags in hand, asking every jōnin for ninjutsu advice?"
The news really had spread farther than he'd expected.
Chiba Shun answered awkwardly, "Please don't laugh at me, senpai."
Nishida Yuichi shook his head.
"There's nothing to laugh about. If I'd had that kind of attitude when I was younger, I wouldn't have wasted so much time taking detours."
Chiba Shun smiled faintly. "Detours are also a kind of accumulation. If you hadn't taken them, you might not have reached where you are now."
Nishida Yuichi looked at him for a moment and then nodded.
"That does make some sense."
Chiba Shun, however, found the man's attitude a little strange.
He was too polite.
And it didn't feel like that courtesy had anything to do with Yozuki Ai.
After chatting a bit longer, Nishida Yuichi finally revealed the reason.
"I've got a son," he said. "He entered the Ninja Academy recently."
Chiba Shun immediately understood.
So that was it.
He smiled and asked, "Is there something I can do for you, senpai?"
Nishida Yuichi said, "My son has both lightning and earth attributes. I used to think there was no need for him to develop Earth Release, but now the village suddenly has earth-style ninjutsu as well."
He paused, then added, "I'd like you to give him some guidance on earth-style techniques."
Chiba Shun answered at once, "Guiding the younger generation that carries the Will of Lightning is part of my duty."
Nishida Yuichi smiled, thought for a moment, and then said, "The Will of Lightning, hm? Interesting."
"So helping you learn genjutsu counts as opening another path for the younger generation of the Will of Lightning?"
"That's right," Chiba Shun said decisively.
Nishida Yuichi chuckled.
Then he asked, "What sort of prisoners do you want to start with? Genin? Chūnin?"
Chiba Shun scratched his cheek and admitted, "I've never tested genjutsu on humans before. Could we start with ordinary people?"
Nishida Yuichi paused, then nodded.
"There aren't many normal civilians held here, but there are a few. Come on. I'll take you over."
And so, Chiba Shun's prison training began.
Before moving on to ninja prisoners, he decided to test every genjutsu he had learned on those ordinary captives first, one by one, so he could understand their effects properly before taking the next step.