[Konoha Year 41 – The Hidden Temple of the Sand]
Since the "first encounter" with the One-Tails, Sayo's visits to the temple had become a ritual of discovery. While he was drawn to the tranquility of Grandpa Bunpuku and the chaotic energy of Shukaku, his engineer's mind had locked onto something else: the physical infrastructure of the temple itself.
For the first time, Sayo ignored the altar and the lamp, instead scanning the room with the precision of a high-resolution sensor. He realized that the "cracks" in the stone walls weren't natural weathering; they were perfectly geometric. The seams in the floor tiles formed a closed-loop circuit. Even the flickering of the oil lamp seemed to pulse with a specific, binary-like frequency.
The entire temple was a massive, decentralized hardware system designed for one purpose: containment.
"Grandpa Bunpuku," Sayo said, pointing to a faint, swirling carving near the ceiling. "These marks... they aren't random, are they? They look like... schematics."
Bunpuku opened his eyes, a flash of genuine shock crossing his face. To the uninitiated, these Sealing Formulas were invisible, blending into the texture of the stone. For a four-year-old to identify their regularity and intent suggested a level of pattern recognition that was practically superhuman.
"These are the foundations of Fūinjutsu—the Art of Sealing," Bunpuku explained, his voice filled with a new level of respect.
"Sealing?" Sayo repeated, his eyes burning with interest. Energy containment and redirection.
"All things in this world possess a flow of energy," Bunpuku said, warming to the topic. "Sealing is the discipline of guiding, restraining, or severing that flow. From a simple storage scroll to the containment of..." He gestured to his own chest. "...something far greater."
"It holds Shukaku by creating a counter-pressure against his energy?" Sayo surmised, instantly translating the spiritual concept into fluid dynamics.
"Precisely." Bunpuku was visibly impressed. "The core lies in the 'Formula'—the patterns you see. Some act as cages, some as bindings, and others as dams to channel and control the overflow."
The monk extended a finger, drawing a simple symbol in the air. A faint trail of blue Chakra followed his movement, leaving a glowing imprint that hummed with a subtle, restrictive force.
"This is the basic Sealing Imprint," Bunpuku said. "The starting point of all profound seals. Its structure is stable, designed to block minor energy leakage."
Sayo didn't blink. His processor-like brain recorded every stroke, the exact speed of the draw, and the intensity of the light. He was performing a structural analysis in real-time. The curves are for stress distribution. The central node is the primary capacitor.
"Hmph! Clumsy! The output efficiency is less than five percent!" A hoarse, arrogant voice erupted from Bunpuku's shadow. "That turning point needs a surge of pressure, old man! Otherwise, your seal is just a leaky bucket!"
Bunpuku smiled helplessly. "It seems Shukaku has his own 'user feedback' regarding the technique."
"User feedback? I've spent decades being the test subject!" Shukaku snarled. "I know exactly where the joints are weak and where the energy bleeds out better than any human!"
Sayo turned toward the shadow, his expression as professional as a consultant. "Then how would you optimize the seal to prevent leakage, Shukaku? Where is the critical failure point?"
The temple went silent. Shukaku seemed taken aback. He wasn't being shouted at or feared; he was being consulted as a Technical Advisor.
"...Hah?" Shukaku sputtered, before leaning into his arrogance. "Obviously, you increase the infusion at the core nodes! Like plugging a high-pressure pipe! And that closing circuit? It's too soft! It needs to be crisp! Decisive! Like a guillotine, not a whisper! Understand? CRISP!"
Though crude, the beast's "complaints" were a goldmine of practical data. Bunpuku was the theorist providing the framework; Shukaku was the quality-control engineer who had found every bug in the system.
Bunpuku nodded, following the "advice." He re-drew the imprint, adjusting the Chakra pulse at the nodes Shukaku had identified. This time, the symbol was blindingly sharp, radiating a much more formidable pressure.
"I see!" Sayo exclaimed. "It's not just the pattern—it's the timing of the energy surge."
In that moment, an unprecedented classroom took shape:
The Teacher: Bunpuku, the high monk of Sealing Theory.
The Lab Assistant: Shukaku, the Tailed Beast with first-hand "stress-test" experience.
The Student: Sayo, the four-year-old engineer who viewed Sealing as Advanced Energy Programming.
Sayo began to absorb the basic runes, mapping them to his knowledge of logic gates and circuitry. He realized that Sealing was essentially "coding" with energy. A circle was a loop; a straight line was a conductor; a jagged mark was a resistor.
Shukaku continued to "heckle" from the sidelines, boasting about how he had broken similar seals in the past. Sayo diligently recorded these "exploit reports," realizing that knowing how to break a seal was the best way to learn how to build an unbreakable one.
Under the dim oil lamp, the three of them—a saint, a demon, and a child—intertwined their voices. Bunpuku watched Sayo's progress with a growing sense of awe. He saw a child who didn't fear power or seek to weaponize it for greed, but someone who sought to understand it.
Perhaps, Bunpuku thought, this boy will be the one to finally stabilize the storm.
For Sayo, the door to a new world had opened. It was a world where mechanics and spirits met—and he was already beginning to write the code.