Within moments.
[You have a new reply]
Naruto's spirits lifted as he immediately opened the reply.
Floor 1 [Wizard Apprentice]: "Perfect, I'm currently in a wizarding world and am a Wizard Apprentice. The wizards here have weak bodies, but they specialize in spiritual power. I have a set of basic Meditation Techniques here that can enhance spiritual power through meditation. In exchange, I hope to obtain cultivation methods regarding 'strengthening the physical body' or 'enhancing life energy.' This body is too weak; I'm even worried I might die suddenly before finishing my experiments."
Wizard? Meditation Technique?
A sharp glint flashed in Naruto's eyes. Their world was one focused on cultivating spiritual power? Coincidentally, that was exactly what he needed. Without hesitation, Naruto immediately replied:
"Deal. I have a set of 'Chakra Extraction Methods' here that can extract the mixed energy, Chakra, from the body and spirit. It provides a certain boost to one's physical constitution."
The "Chakra Extraction Method" Naruto provided was the common extraction method taught at the Ninja Academy. This kind of thing was basic and common in the Shinobi World; one could buy it at any bookstore for a few hundred Ryo. Almost every shinobi knew it, and they were all more or less the same. It was a widely verified technique. It might not be incredibly powerful, but it was certainly effective and harmless.
Afterward, the two exchanged their techniques in a private chat. After the trade, the [Wizard Apprentice] seemed to remember something and added:
"The energy systems of different worlds vary. These methods and techniques are for reference only; you must never copy them exactly. Otherwise, if your brain explodes, don't blame me for not warning you. However, you can modify it based on your local conditions. Maybe the effect will be better, but who knows. Good luck."
Having said that, the [Wizard Apprentice] went offline.
[Ding!]
[Suggestion recorded: Modified Meditation Technique.]
[Mission Requirement: Localize the Meditation Technique and create a spiritual cultivation method suitable for the Shinobi World.]
[Mission Reward: A-rank Treasure Chest.]
"A-rank?" Naruto's brow twitched.
This indicated that the "Modified Meditation Technique" mission was extremely difficult, but once successful, the rewards would be immense. Furthermore, this was the first time he had learned about the incompatibility of energy systems between different worlds. When he learned the Breathing Technique, he hadn't felt any so-called difference in energy systems at all.
But thinking about it carefully, it wasn't that strange. As the name suggests, the Breathing Technique is just a set of universal training skills, whereas other energy systems are closely tied to their respective worlds. This Wizard Apprentice probably also needed to localize the "Chakra Extraction Method" he had provided.
Subsequently, Naruto began browsing through the so-called Meditation Technique. By the time he finished, he finally understood why the [Wizard Apprentice] had added that disclaimer at the end. The Meditation Technique of the wizarding world required condensing runes in the mind and capturing elemental particles to enhance spiritual power.
And elemental particles were a type of free energy unique to the wizarding world. Runes were energy circuits discovered by wizards over tens of thousands of years to capture and domesticate these particles. Although shinobi could summon wind and rain, Naruto had never heard of anything like elemental particles.
Naruto sighed and tossed the Meditation Technique aside. "Could this be a dead end?"
No, that's not right.
"The method is static, but people are adaptable." After a moment of reflection, Naruto began to re-examine that theory. "Setting aside runes and elements, the core theory of this Meditation Technique is—construction! By building a house within the spiritual world to stabilize the Sea of Consciousness and increase its capacity. Since there are no elemental particles to use as bricks, I'll use Chakra; since there are no runes to use as blueprints, I'll find Yin Release theories myself!"
Although the path ahead was unknown and the process might be fraught with risk, as Naruto looked at the special pass on the table, a curve formed at the corner of his mouth.
"As long as the theoretical logic is sound, there's nothing I can't do. After all, I am a genius," Naruto pushed up his glasses, the lenses flashing with a reflection, "Certified by the Hokage."
...The next morning.
After sending a Kage Bunshin to the Ninja Academy and dispatching a large number of clones to train and grind proficiency, Naruto arrived at the Konohagakure Library. This domed building was located in a corner of the village. Compared to the bustling Mission Hall, this place seemed exceptionally quiet.
After all, for most shinobi who valued strength and practical combat, rather than flipping through boring theories here, it was more practical to throw a few more kunai or do a few more push-ups.
When Naruto placed that special pass with the Hokage's seal on the counter, the Tokubetsu Jonin guarding the library nearly had his eyes pop out. He checked it three times before he dared to confirm that it was indeed a special pass issued by the Hokage. Generally speaking, only shinobi who had performed great deeds for the village would be granted reading access to the second floor.
"You may enter the second floor to read at your leisure, but borrowing books requires registration, and you cannot take more than one at a time."
"Understood, thank you." Naruto nodded politely, ignored the other party's strange look, and stepped onto the spiral staircase.
The second floor housed various C-rank and below Ninjutsu, Hiden techniques, and a large number of precious historical documents. Naruto walked to the section on Yin Release and Genjutsu and formed hand seals.
Poof!
A clone appeared beside him. Without a word, the clone already knew its task. It nodded to the original and began flipping through the books. Naruto's purpose for coming this time was to study theoretical knowledge regarding Yin Release nature transformation, the substance of spiritual energy, and the effects of Genjutsu on the brain.
With the boost from [Eidetic Memory], Naruto and his clone activated human-scanner mode. Kori Shinchuu no Jutsu, Magen: Narakumi no Jutsu... book after book was opened and closed. As time passed, the expectation in Naruto's eyes gradually cooled, and his brow began to furrow.
Two hours later.
Snap!
Naruto closed the "Compendium of Yin Release Ninjutsu" in his hand and let out a sigh.
"Too superficial." Naruto pushed up his glasses, his tone carrying unconcealed disappointment. "Is this the theoretical system of the Shinobi World?"
Naruto looked closely for a long time before he could see between the lines; the entire book was densely packed with the concept of "killing people." Everything taught in the books was at the application level. It was like being given a gun and taught how to pull the trigger, but without being taught the formula for gunpowder.
"It seems standing on the shoulders of giants is unlikely; I'll have to forge a path myself."
Just as Naruto made up his mind to open a path on his own, a voice rang out in Naruto's ear.
"Junior, are you very interested in Genjutsu?"