[Historical Setting: Year 45 of the Shinobi Calendar – Pre-Third Shinobi World War]
The transition was a violent assault of sensory deprivation. Cold, crushing pressure, and a suffocating darkness defined his existence until, suddenly, the world fractured into a blinding, hazy light that pierced his fragile eyelids.
Liu Yu's consciousness clawed its way out of the abyss, but panic immediately seized him. He couldn't move. He couldn't speak. His very eyes felt fused shut by a leaden weight. He sensed himself being hoisted by calloused hands, surrounded by a cacophony of muffled, urgent voices. The language was foreign, yet the cadence of desperation and clinical tension was universal.
A wave of physiological exhaustion, far beyond anything he had felt during forty-eight-hour coding marathons, dragged his mind back toward the void. Just before the darkness reclaimed him, he heard a woman's sharp, agonized cry—a sound of finality that chilled his newborn blood—followed by the frantic rhythmic thud of receding footsteps.
When he finally regained a flicker of awareness, he forced one eye open.
The world was a blur of sepia tones. A flickering lamp, fueled by pungent animal fat, cast dancing shadows against walls of rough-hewn, yellow-brown sandstone. The air was thick, tasting of parched dust and the bitter, astringent scent of medicinal herbs.
He tried to tilt his head, but his muscles were unresponsive. He felt dangerously hollow, his body a fragile vessel where every heartbeat felt like a mechanical struggle against friction.
Where am I? his mind raced, the logic of a systems engineer struggling to boot up. I was at the plant... debugging the CNC production line.
His last concrete memory was the comforting hum of automated spindles and the green glow of scrolling logic gates on his monitor. As a thirty-year-old automation engineer, his life had been defined by precision and metal. His only reprieve from the grind had been his private obsession: a blueprint for a high-mobility, pilotable bipedal frame—his "Gundam."
Sudden cardiac arrest? Overwork? The diagnosis was logical. The result, however, was impossible.
Rebirth. Transmigration. He analyzed the data points: the miniature limbs, the lack of motor control, the primitive environment. It was the ultimate "black box" scenario—he had been reincarnated.
A hell-mode start, Liu Yu—now Sayo—thought with a dry, internal irony. He could feel the systemic failure of his new biology; his pulse was thready, his constitution brittle.
"Haruko... Haruko..." A hoarse, shattered voice broke the silence nearby.
Sayo strained his vision. A broad-shouldered man in rugged gray tactical gear knelt by a low cot. A metal forehead protector, etched with an abstract hourglass symbol, was tied around his head. His frame shook with violent, rhythmic tremors as he gripped a pale, lifeless hand.
On the bed lay a young woman. Her features were beautiful but waxy, her eyes closed in a permanent sleep. The metallic tang of blood lingered in the air. Sayo felt a sudden, involuntary pang in his chest—not from his own memories, but from the raw, biological grief of the body's DNA. This woman, his mother, had traded her life for his.
"Sigh..." A weary, heavy sound echoed from the corner.
Sayo noticed a third figure. A woman stood over them, her expression a mask of professional gravity. She carried an aura of immense, weathered authority. Sayo's engineer's eye caught the drying blood on her sleeves.
"Sharyu, find your resolve," the woman said, her voice like grinding stone. "Haruko was a kunoichi of the Sand. Her final mission was to ensure this child's survival."
The man, Sharyu, looked up. His eyes were a roadmap of burst capillaries and grief. He turned his gaze toward the swaddled Sayo—a look of agonizing conflict between the love for a son and the resentment for the cost of his birth.
"Elder Chiyo..." Sharyu rasped. "I... I don't know if I can..."
The woman, Chiyo, stepped forward and checked Sayo's vitals. Her brow furrowed into deep trenches. "Premature. Congenitally deficient. His chakra pathways are constricted, and his constitution is like scorched parchment. He will face a hard road if he is to survive this desert."
Sayo's heart sank. He understood her perfectly. Having spent years coordinating with Japanese heavy-industry firms, the language was second nature to him. But the technical assessment was grim. In a world of superhuman ninjas, he was a "defective unit."
Chiyo looked at the broken man before her. "In your current state, you are a liability on the front lines. The Third Kazekage cannot afford distracted soldiers in the current climate."
She paused, calculating. "The Maintenance Squad Four has been without a lead since the veteran's retirement last winter. You will take the post. You'll be responsible for the upkeep and repair of the village's Puppet Brigade arsenal. It is a rear-line position. It will give you the access to the tools and time needed to keep this boy breathing."
Sharyu looked at his son, then at his fallen wife, and finally nodded with a heavy, solemn finality. He reached out a rough, calloused finger and brushed Sayo's cheek.
"From this day... your name is Sayo," he whispered, a vow directed more to the dead than the living. "I will make sure you endure."
Sayo... Sunagakure?
The pieces of the puzzle clicked into a terrifying whole. The hourglass symbol, the puppets, the names. This was the world of Naruto. Not the lush, privileged forests of Konoha, but the brutal, impoverished wasteland of the Hidden Sand. He had no legendary bloodline, no "System" interface appearing in his vision, and no Nine-Tails. He was a sickly infant in a village on the brink of economic collapse and world war.
His only "Golden Finger" was a brain filled with thirty years of advanced mechanical engineering, robotics, and automation logic.
No magic, no cheats... just physics and chakra, Sayo thought as exhaustion began to override his consciousness. If this body is weak, I will build a better one. If this village is dying, I will re-engineer it.
Before the darkness took him again, his final thought was focused: Survive. Adapt. Overcome. I will not die in the dust.
The infant closed his eyes, his breathing faint but rhythmic—the first steady idle of a machine that would eventually reshape the shinobi world.