Chapter 35: I'm the Number One Puppet Master, None of You Compare
"You're late, Rinko."
Deftly navigating the rows of bookshelves and desks, Hiiro Rinko pushed open the door to a private reading room. The first thing he heard was this slightly teasing 'scolding.'
After all, for the past three years, it had always been the boy waiting for others, never the other way around.
No, looking at his appearance now, 'young man' was probably more appropriate.
The Uzumaki Clan's physique, combined with the superhuman digestive ability he'd gained from his Binding Vow, had caused Rinko's height to shoot up over the last three years. He'd grown from just over 120cm to more than 150cm.
Normally, a child from an average family at this age would only be around 130cm. Even children from shinobi clans wouldn't be much taller than 140cm.
After all, with the productivity and nutritional conditions of this era, it was difficult to provide a child with sufficient nutrients like in modern times. This was the other main reason Rinko had chosen 'digestion' as the reward for his Binding Vow.
"Ah, I ran into an acquaintance. We talked for a bit."
Rinko unbuttoned his trench coat, hung it on the hook behind the door, and then sat down in the chair opposite Karura and Pakura. "I didn't keep you two waiting long, did I?"
Although it was a question, his tone was completely flat, sounding more like a statement. Knowing the girls as he did, how could he not know when they would arrive?
"Ehehehe~"
As expected, Karura, who was sprawled on the table, let out a soft, silly giggle that was more convincing than any answer.
Pakura, her chin resting on her hands, simply blinked and gave him a small smile.
Compared to Rinko, the girls hadn't changed as dramatically. Karura's face was still round, but she'd lost her baby fat. Pakura's figure had become even more slender—perhaps a side effect of circulating her Fire-nature Chakra.
In another two years, the girls would hit their main growth spurt.
"Here are the charts you asked me to help with."
Seeing Rinko sit down, Karura sat up straight. With a 'praise me!' look on her face, she pulled a stack of forms from her bag and pushed them over.
"Hai, hai... Good work, good work."
He first reached out to rub the little rabbit's head before picking up the charts to look them over. All Pakura could do was pout. Her personality just wasn't suited for fawning over Rinko like Karura could.
But her 'area of advantage' wasn't here, anyway. Karura couldn't serve as a sparring partner for Rinko.
Thinking this, the girl's smile became more pronounced as she watched Rinko.
Even though they had gotten used to each other, it didn't mean the competition between Karura and Pakura had disappeared. A young girl's heart isn't that generous.
Rinko, long prepared for this, didn't interfere, just quietly writing on the forms.
These were the daily physical metrics he had been tracking for the three of them. Displaying it in a chart helped him plan their future training regimens more easily.
Seeing this, Karura and Pakura also began their reading for the day. For a time, the only sounds in the room were the turning of pages and the occasional scratching of a pen.
At this moment, one 'thread' of Hiiro Rinko's dual-core, quad-thread 'artificial' intelligence was processing the charts in his hand. The other three threads were conducting different research—
The design of ninja tools and Puppets; theoretical applications of Water Release (Suiton) Chakra; and the core construction of Yin Release and Yang Release Chakra.
After Yūsa had finally made peace with his own relatively mediocre talent, Chiyo had officially passed on her knowledge of the Puppet Technique to Rinko.
But that said, the Puppet Technique itself wasn't of much use to Rinko. After all, in his past life, he had designed and built the puppets used by Muta Kokichi—Mechamaru—and even his final weapon, 'Ultimate Mechamaru Mode: Absolute.'
In terms of puppet design philosophy and experience, he could, without exaggeration, claim to be far ahead of the entire Land of Wind and the Shinobi World.
After all, the Puppet Technique here was created by the Second Kazekage, Shamon, and was only twenty or thirty years old. It was still a technique meant to compensate for a lack of military force, and it still required a Puppet Master to use Chakra threads. This showed it was far from its complete form.
Muta Kokichi's 'Heavenly Restriction', which gave him a Cursed Energy manipulation range that covered all of Japan, was a unique exception. But even so, puppets in the Jujutsu World didn't need to be manipulated by hand with threads, not to mention the existence of Cursed Corpses (Jugai) that could move completely autonomously.
Adding in all the design concepts Rinko had collected from other sources for inspiration, he really couldn't help but look down on the Puppet Technique here.
This was why, when Chiyo first found him and her puppet burst through the door, he had been able to spot its weaknesses instantly.
But even so, the clever little mechanisms in the puppets still had aspects worth learning. What Rinko was doing now was extracting the useful details from the Puppet Technique and integrating them into his own puppet-manufacturing system for further optimization.
And, of course, making some convenient new gadgets.
On another front, Rinko currently possessed both Wind and Water Chakra natures. After receiving Matasaburō's teachings, he had no more room for improvement in Wind Release for now, other than simply learning more Wind Jutsu.
But Water Release (Suiton) was different. Unlike other elements, Suiton was similar to Sunagakure's Sand Manipulation, as it heavily relied on environmental conditions.
Just as Sand Jutsu is overwhelmingly powerful in the desert, Water Jutsu is at its best in an environment with abundant water.
Unlike Wind, Fire, and Lightning, which tend to directly convert Chakra into the corresponding element, a large percentage of Water Jutsu rely on using an existing water source.
This is a trait it shares with Earth Release (Doton), which also uses ambient rock and stone. The difference is that earth and stone are far more abundant on the continent than water sources.
Therefore, being able to use Water Release in a waterless place has always been the mark of an elite Suiton master.
And Sunagakure's natural environment clearly lacks the moisture required for most Water Jutsu. Even if he converted Chakra directly into water, the cost would be several times higher than in a normal environment.
Since he couldn't even use it, Sunagakure naturally had a severe lack of Suiton study materials. In this situation, Rinko could only resort to theoretical 'brain simulations.'