Shintarō Mayoi's story didn't begin with a perfected "House of Horrors." It began with fear, curiosity, and the stark reality of a world that didn't care for the weak.He arrived in this new, chakra-filled world at the awkward age of thirteen, a time when a boy is most vulnerable and impressionable. The memories of his past life—a life of university lectures on social psychology, popcorn-fueled horror film marathons, and the sterile safety of a modern world—were a confusing, haunting counterpoint to the dirt, the danger, and the raw survival of his new home.His village was small, nestled in a clearing surrounded by a simple stone wall, a vulnerable island in a sea of forest. The peace was a fragile illusion, shattered every few months by the arrival of bandits or rogue ninja looking for easy pickings. They weren't powerful shinobi armies, but they were powerful enough. They killed, they stole, and they left the villagers in a state of quiet despair.Shintarō watched, and his past life's knowledge began to coalesce into a single, overriding goal: this could not happen again.He couldn't fight them with physical strength. He was a boy, not a ninja with decades of training. He had to use what he knew.His self-education began in earnest. He scavenged old scrolls and spent hours practicing basic chakra control. He learned about genjutsu—illusions cast by manipulating the flow of chakra in the victim's cranial nerves. To most ninja, genjutsu was a support skill, a distraction. To Shintarō, it was the key. It was VR. It was the ultimate psychological experiment.He experimented in secret, starting with small, harmless illusions on himself. A drop of water that sounded like a waterfall. A rock that felt like velvet. He studied his own reactions, how the brain filled in the gaps, how a small sensory input could become a perceived reality.
His reading of psychology textbooks merged with the principles of chakra manipulation. He began to understand that a ninja's greatest strength, their iron will and pride, was also their greatest weakness. They trained for physical battle, but not for a war with their own minds.At fourteen, he began his first real-world tests.
He would capture a badger or a small, aggressive ninja-hound that strayed too close to the village. Instead of killing it, he'd lay down a simple seal and watch.He wouldn't make the badger see a monster. He'd just make it feel a slight chill. He'd make a single leaf in its peripheral vision seem to flutter when the air was still.
The animal would become paranoid, agitated, running in circles until it collapsed from exhaustion. He observed the "fight or flight" response, and how a lack of a clear enemy turned that response inward, creating terror and confusion.He cultivated his strange garden of psychoactive plants, learning which burned with a clean flame and which produced a thick, mind-altering smoke.
He learned about the amygdala, the fear center of the brain, and how a physical chemical and a chakra-based illusion could work in tandem to bypass even the strongest mental defenses.By sixteen, the plan was clear. The defense wouldn't be a sword, it would be a mirror. It would be a weaponized, environmental trap that targeted the ego and the brain's natural functions.The next bandit raid was his final inspiration.
He watched from the shadows as they swaggered into the village, confident and cruel. He couldn't stop them that time, and the memory of their arrogance, of the fear in the villagers' eyes, hardened his resolve.
He spent the next two years perfecting his sealing techniques, laying the intricate, subtle network around the perimeter of the clearing. It wasn't one powerful seal, but hundreds of low-level, continuous ones that created a persistent, ambient effect.
He built in the "secret key" and the "endless loop," not out of mercy, but out of a cold, scientific understanding of his opponents' nature.
By the time he was eighteen, the system was complete. He was no longer a boy who watched horror movies; he was an architect of horror. He had created the perfect weapon, one that didn't require him to land a punch or throw a kunai. It required only that his enemy be a human with a mind to break and pride to exploit.
He was ready for the next "visit." And as the four ninja from the Hidden Stone village now wandered his loop, chasing shadows and questioning reality, he knew his work was good. His home was safe. The price was just a little bit of sanity, a currency he was willing to spend on anyone foolish enough to trespass.