A few days later, while pretending to play with other children, Itachi approached the room where the instructors stored practice materials. There, he found an old manual with symbols he had seen before: circles, chains, and chakra marks. It was a basic tome on storage seals, forgotten on a shelf.
He opened it delicately. The strokes hypnotized him. "This isn't just writing… it's a language to speak to chakra."
Just then, an instructor surprised him leafing through the book. "What are you doing with that, Itachi? It's too complicated for a child your age."
Itachi looked at him seriously. "I want to learn. If I understand the seals, I can better protect my family."
The man fell silent. There was something in the boy's gaze that didn't belong to a child: determination, maturity, fire. Finally, he sighed. "Alright, I'll teach you the basics. But don't expect much… fūinjutsu is neither easy nor fast."
That afternoon, he learned the essentials: The concept of chakra matrices: how a seal wasn't a decorative drawing, but a circuit that guided energy. The base kanji to contain, release, and stabilize chakra. Simple storage seals, like storing a small stone in a scroll.
When he managed to seal a simple stone in a piece of paper, Itachi felt a mix of pride and anxiety. It was nothing compared to what he knew existed, but it was a start.
As he returned home, he thought: "If I master this, I can create my own tools. I won't have to rely on brute force alone."
That night, while secretly reviewing the symbols, he understood something else: seals were a way to expand the mind in another direction. If genjutsu taught him to manipulate senses and the Rasengan to concentrate chakra, fūinjutsu opened the door to the hidden language of chakra itself.
The road would be long, but he already had a plan: Learn the basics from the instructors. Gain the trust of the clan elders to access more advanced scrolls. And, if he was lucky, find a true expert within the village.
The boy closed his eyes, convinced: "It doesn't matter that I'm three. As long as they underestimate me, I will advance in silence."
The days passed slowly. Thirteen, to be exact. During that time, Itachi continued to explore the fundamentals of fūinjutsu. Every stroke he learned was like a line of code in a secret language.
The boy understood that this wasn't just writing: it was the programming of reality itself. With a correct kanji, he could order chakra to "store," "block," or "expand." He could also store energy and, by passing it through certain characters, the chakra would acquire properties like electricity, fire, or water.
He even discovered that it was possible to add "switches," small conditional seals that determined when certain circuits should be activated. Some characters gave chakra structure, others allowed him to regulate the intensity of its flow.
It was like discovering that the entire world responded to a precise and universal syntax.
Although his progress was modest—storing a stone, tracing a chakra-stabilizing mark—his mind already saw an infinite future of possibilities. "One day I'll create my own seals," he thought, "codes no one has ever seen before."
But while he was dreaming of the future, on the battlefield, his father was facing a present stained with blood.
Fugaku led a small Uchiha unit sent to Kusagakure, a disputed territory during the Third Great Ninja War. Reports suggested that the shinobi of the Rock were retreating, but Fugaku suspected the opposite.
His team was made up of cousins and close relatives, men he had trained with since childhood. Among them, a comrade he considered almost a brother: Shinji Uchiha, a master of tactics and advanced shurikenjutsu.
The mission seemed simple: secure a strategic gorge. However, as soon as they arrived, they understood the truth: it was a trap.
Dozens of shinobi from the Rock emerged from the ground like specters, surrounding the unit. The terrain itself was against them.
"Ambush!" Shinji shouted, throwing a rain of shuriken coated in fire.
Fugaku immediately responded, unleashing a Katon: Gōkakyū no Jutsu that lit up the sky like a red sun. Several enemy silhouettes fell charred, but the others hid under the rock, attacking from impossible angles.
The fight was brutal. The Uchiha resisted with their red eyes glowing, anticipating movements, responding with fire and steel. But the ambush was too well-planned.
In the midst of the chaos, Fugaku saw an enemy emerge from the ground behind Shinji. "Shinji, behind you!"
It was too late. A rock spear pierced his friend's chest. The choked scream was etched into the air.
Blood splattered the field, and something inside Fugaku broke. Time seemed to stop. His gaze blurred in a whirlwind of pain, fury, and despair.
In that instant, the world changed: his Sharingan evolved.
His pupils distorted, revealing a new pattern. The Mangekyō Sharingan.
With his new power, the battlefield was transformed. Every enemy movement was visible, every strategy revealed before it was executed. Fugaku's fury translated into lethal precision.
He summoned a fire jutsu empowered by his Mangekyō, a sea of black flames that razed the ground. The enemies' screams echoed as they were consumed without mercy.
The ambush ended in minutes. The survivors fled underground, leaving behind the smell of ash and iron.
But victory brought no relief. Fugaku fell to his knees in front of Shinji's body, his friend, his brother-in-arms. The Sharingan still burned in his eyes, but the emptiness in his chest was even greater.
"We shouldn't have trusted the information… they knew where we would be," he murmured, with a dark premonition.
Thirteen days after his departure, Fugaku returned to the clan. He carried with him the invisible wound of loss and a new power he hid under the leader's mask.
Itachi watched him in silence. He felt the heaviness in his aura, the way his father walked more slowly, his shoulders weighed down by shadows.
At that moment, the boy understood something: War was not about glory or honor. It was about loss. It was about paying with blood the price of power.
Itachi, at just three years old, looked at his father and thought: "If I want to change the clan's destiny… I need to see beyond strength."