Hiroshi sat cross-legged in his small workshop, a faint smell of burnt resin lingering in the air. In front of him were several crude glass containers filled with various mixtures, some still bubbling slightly. His hands were sticky, his face smudged with soot, but his eyes gleamed with determination.
Making fuel was proving to be much harder than he initially thought. Resin was a good base—easy to find and harvest in Sunagakure's arid environment—but the challenge was creating a stable, efficient mixture. His first attempt had resulted in a sticky, tar-like substance that barely burned. His second attempt had exploded in a brief, uncontrollable flame that nearly singed his eyebrows. But this time, he was getting closer.
"I need something that burns hot and steady," Hiroshi muttered, swirling the mixture in his glass container. He had added a combination of alcohol distilled from dates and a small amount of powdered magnesium he managed to procure from the market. The resin acted as a binder, but balancing the ratios was tricky. Too much alcohol, and it burned out too quickly; too much resin, and it clogged the container.
He sighed and leaned back, wiping his forehead. "This would be so much easier if I had better equipment," he thought. But he quickly shook the thought away. Complaining wouldn't get him anywhere. He adjusted the nozzle of his makeshift fuel sprayer, testing how the liquid ejected. A small, controlled flame danced when he lit it.
"Better. Much better."
Once the fuel was stable enough, Hiroshi shifted his focus to the container. It needed to be lightweight, durable, and capable of withstanding high temperatures without cracking or leaking. He had already sketched several blueprints, but each design came with its own problems.
Using clay was out—it was too brittle. Metal was an option, but shaping and sealing it without proper tools was nearly impossible. Then he thought of combining resin with sand to create a reinforced composite. After a few failed experiments, he finally managed to create a container that could hold the fuel without cracking under heat.
"This should work for now," Hiroshi thought, though he knew it wasn't perfect. He still had to test it under combat-like conditions, but it was a step forward.
As he worked, his mind wandered to upgrades he could add to the puppet. A camera or thermal sensor would be invaluable in tracking enemies, especially in Sunagakure's harsh desert environment. The idea excited him for a moment—imagine a puppet that could "see" heat signatures or transmit live visuals!
But reality quickly set in. Electronics in this world were still in their infancy. Vacuum tubes were bulky and inefficient, and creating something compact enough to fit inside a puppet was out of the question.
"This isn't going to work," Hiroshi muttered. His fingers drummed against the table as he thought back to his previous life. "If I had access to semiconductors… things would be different."
He leaned back, staring at the ceiling. "Semiconductors transformed the world. They were the backbone of modern technology—computers, phones, satellites, even military-grade drones. None of that would've been possible without them."
He remembered reading about the history of semiconductors in his old world: how germanium and silicon had replaced vacuum tubes, leading to the creation of transistors, which in turn sparked the age of microelectronics.
"But making a semiconductor… that's not easy."
Hiroshi started listing the problems in his mind. First, he would need pure silicon or germanium, which required advanced refining processes. Then, he would need to create doped regions with precise impurities to make it conductive in specific ways. Even if he somehow managed that, fabricating a working transistor would require precise equipment to handle microscopic layers.
"Even if I work day and night, it'll take at least five years to build anything close to a functional transistor," he thought. "And that's if I'm lucky."
Still, the idea of creating semiconductors lingered in his mind. It was a long-term goal, something that could revolutionize this world if he ever succeeded. But for now, he had to prioritize.
"I can't get distracted," Hiroshi reminded himself. "The first puppet has to be functional. I can add upgrades later when the technology catches up—or when I figure out how to create it myself."
He looked at his blueprint of the flamethrower mechanism. It was simple but effective, relying on the fuel and container he had just developed. "This will work," he thought. "It's not perfect, but it's a start."
With renewed focus, Hiroshi began refining the fuel mixture and testing the container. His mind buzzed with ideas for future projects, but for now, his priority was clear: to create a puppet that would lay the foundation for his future innovations.
As the small flame from his fuel sprayer flickered in the dim light, Hiroshi smiled. "One step at a time," he said to himself. "One step at a time."
Hiroshi carefully adjusted the flame of his makeshift burner, his eyes narrowed in concentration. A small glass vial filled with a resin mixture bubbled gently as he tested yet another formula for his fuel. It was late at night, the quiet hum of the desert wind outside his window serving as the only backdrop to his focused work.
He sighed, leaning back in his chair. The experiment was progressing, but slowly. The fuel was stable enough to burn consistently, yet it lacked the burst of intensity he needed for flamethrower. He rubbed his temples, feeling the familiar strain from hours of concentration.
As he stared out into the dimly lit room, a strange sensation tugged at the edges of his awareness. It was faint, like the echo of footsteps he couldn't quite hear, but it sent a small shiver down his spine. For a moment, he thought he was imagining it.
"Was that… someone?" he whispered to himself.
He stood up, staring out the window into the darkness. Nothing moved except the swaying shadows of nearby palm trees. After a moment, he shook his head and returned to his seat.
"Must be the wind," he muttered, though the feeling lingered.
Still, it wasn't a total loss. His faint awareness of something—whatever it was—meant his chakra sensing was improving, even if progress was slow. Every night, he practiced, focusing on extending his chakra to sense his surroundings, but the results were minimal. It frustrated him, yet he knew mastery required patience.
---
A knock on his door pulled him out of his thoughts.
"Hiroshi, come eat dinner!" his mother's voice called out.
"I'm busy!" he replied automatically, not moving from his seat.
The door creaked open, and Kokoro stepped inside, her arms crossed. She was a small woman, but her presence could fill a room when she was annoyed.
"Hiroshi Kazetani, I know you're working hard, but you can't survive on ambition alone. Come eat."
Hiroshi sighed, realizing there was no escape. He followed her to the small dining area, where his father was already seated, his usual stern expression softened by the aroma of food.
As Hiroshi sat down, Kokoro set a steaming pot of lentil stew on the table. "You've been locked in that room all day. Are you even sleeping?"
"I'm fine, Mom," Hiroshi said, ladling stew into his bowl. "I'm just… working on something important."
Hachirou grunted, taking a sip of tea. "Important, huh? You mean that project of yours? What is it this time—another one of your wooden toys?"
"It's not a toy!" Hiroshi protested. "It's a puppet. And it's going to have a flamethrower."
Kokoro gasped, her ladle clanging against the pot. "Flamethrower? What on earth are you building, Hiroshi? A weapon?"
"Technically, yes," Hiroshi admitted. "But it's for training! And… for defense."
Hachirou smirked, shaking his head. "You're six, Hiroshi. Maybe focus on not burning down the house first."
Kokoro shot him a look. "Don't encourage him! What if he gets hurt?"
"I'm being careful," Hiroshi reassured her. "Besides, you always say I should aim high, right? This is me aiming high."
His mother sighed, but there was a glimmer of pride in her eyes. "Just… don't overwork yourself. And no flames in the house, understood?"
"Yes, Mom," Hiroshi said, suppressing a grin.
---
After dinner, as Hiroshi returned to his room, he found himself smiling. His parents' concern annoyed him sometimes, but it also reminded him of what he was working for.
Sitting back at his desk, he glanced at the small vial of resin fuel. It wasn't perfect yet, but he'd get there. Just like his chakra sensing, progress came in small steps.
"Tomorrow," he whispered to himself, "I'll make it work."
As the night deepened, he let his chakra drift again, focusing on the faint presence he had felt earlier. It wasn't clear, but it was something. And for now, that was enough.
---
The sun was dipping low in the sky as Hiroshi made his way to Nakamura's workshop. Located on the quieter side of the village, the workshop was a modest space filled with the hum of tools, the faint scent of metal shavings, and rows of carefully arranged supplies. Hiroshi paused at the entrance, taking a moment to steady himself before knocking.
"Come in!" Nakamura's voice rang out, calm but commanding.
Hiroshi stepped inside, greeted by the sight of his sensei bent over a workbench, fiddling with what looked like a half-finished gear mechanism.
"Ah, Hiroshi," Nakamura said without looking up. "What brings you here? Don't tell me your experiments set something on fire again."
Hiroshi huffed. "That only happened once. And I wasn't even trying to make a flamethrower back then!"
Nakamura chuckled and waved him over. "Alright, kid. What's the problem this time?"
---
Hiroshi set his notes and sketches on the workbench, explaining his struggles with creating a fuel container that was durable, heat-resistant, and lightweight. Nakamura listened patiently, his expression thoughtful as he tapped a finger against his chin.
"You're trying to make it all from one material?" Nakamura asked, finally picking up one of Hiroshi's sketches.
"Well, yeah. I thought it would be simpler that way," Hiroshi admitted.
"There's your problem," Nakamura said, pulling out a sheet of thin metal and a small jar of resin. "What you need is a combination. Use a metal shell for durability, and coat the inside with resin for heat resistance. That way, the fuel won't eat through the container, and it can handle higher temperatures."
Hiroshi's eyes widened. "That… actually makes so much sense. Why didn't I think of that?"
"Because you're still learning," Nakamura said with a smirk. "And because sometimes it takes a fresh perspective to see what's right in front of you."
As Hiroshi scribbled notes furiously, Nakamura leaned back against the bench. "By the way, what are you planning to call this fiery creation of yours? Please don't tell me it's something ridiculous like Fireball-kun."
Hiroshi looked up, startled. "I… actually hadn't thought about a name yet."
---
The rest of their discussion was punctuated by Nakamura throwing out increasingly absurd suggestions.
"How about Burninator?"
"No."
"Smokey Scorcher?"
"Absolutely not."
"Hothead?"
Hiroshi groaned. "Sensei, I'm serious!"
"So am I!" Nakamura grinned. "But fine. What's your idea?"
Hiroshi paused, tapping his pencil against the edge of the bench. His mind wandered to the determination he felt whenever he worked on the project—the drive to create something that would push the limits of what a puppeteer could do.
"Rengoku," Hiroshi said finally, the word rolling off his tongue.
"Hmm. Not bad," Nakamura said with a nod. "Has a certain weight to it."
Hiroshi smiled faintly. "It means 'purgatory.' It fits, don't you think? A puppet that controls fire, something that can turn the tide in a fight… and it's only the beginning."
Nakamura clapped a hand on his shoulder. "Well, just don't burn down the village, alright?"
---
That night, Hiroshi worked late into the evening, armed with Nakamura's advice. He carefully layered resin inside a small metal shell, testing its durability by applying heat to the prototype. After a few tries and adjustments, he finally had a container that passed his tests.
The fuel mixture was another matter. Resin-based fuel proved efficient, but Hiroshi experimented with adding small amounts of oil and powdered additives to boost its energy output. The workshop filled with the faint smell of burnt materials, and Hiroshi made a mental note to improve ventilation in his workspace.
By the time he sat back to admire his progress, he felt a wave of satisfaction wash over him. His project was finally taking shape. With the container and fuel ready, all that was left was to integrate these components into the puppet itself.
And now, it had a name.
"Rengoku," Hiroshi murmured, a spark of pride lighting up his eyes.
The foundation was set. All that remained was to bring his creation to life.