The sun had barely risen when Itachi found Renji in the courtyard. "Today, I'm going to teach you something," Itachi said with a serious tone. "But you must promise to concentrate."
Renji nodded enthusiastically. His eyes were shining, full of curiosity and respect. Although he didn't have trained chakra, he was willing to try.
Itachi began by explaining the basics: "Chakra is energy that flows within you. If you learn to feel it and guide it, you can control your body and your techniques."
He showed him how to breathe to generate chakra, how to center it at a single point, and how to gently direct it toward his hands. At first, Renji felt nothing, but Itachi had an idea.
"We're going to use seals. You'll stand in the center of these, and they will guide the energy toward you."
He drew several seals on the ground, combining shapes and patterns that acted as an antenna and a resonance guide. Then he instructed Renji to stand in the center. "Now, breathe deeply and feel the flow. Don't try to force it; let the seals do their work."
Renji closed his eyes and breathed. At first, nothing happened, but little by little, he began to feel a strange tingling in his hands and feet. Itachi smiled. "See? This would normally take days to feel, but the seals speed up the process. Just concentrate on staying calm and letting the energy flow."
Then came the practical exercises. They ran around the courtyard, blocking invented movements, trying to control energy while moving, dodging, and releasing small impulses. Itachi constantly corrected him: "Don't concentrate everything in one place. Distribute it. Maintain balance."
Renji began to understand that chakra wasn't just power, but a tool, a guide, and a pattern, and that controlling it required patience and observation. Although he couldn't perform a complete jutsu, he was starting to feel like a true ninja, learning discipline and concentration.
At the end of the day, both boys sat in silence, looking at the night sky. Renji was breathing hard but was satisfied. "Thank you, Itachi…" he said. "I've never felt anything like this before."
Itachi smiled. "It's just the beginning. One day you'll be able to use this for more things… even to understand patterns that no one else sees."
As the moon rose, Itachi knew that teaching Renji not only strengthened the other boy but also solidified his own understanding of chakra and how he could manipulate it through seals and guided flow. It was another step toward his secret path.
Life for Itachi became busier in the following weeks, as he had many fronts of research and growth to work on little by little. The good thing was that he was very young.
Three months had passed since Itachi awakened in this world. The boy had grown in knowledge and discipline beyond what anyone could expect from a child his age. His days were divided between morning training with Fugaku, sessions with Shisui, and nocturnal experiments with seals and chakra absorption alongside Renji.
But that routine was about to change. One morning, Fugaku received an emergency order: he had to rejoin the battlefront in Kusagakure, this time on a mission that would surely last for several months. "Itachi," he said before leaving. "Use this time to train intelligently, take care of your mother, and don't worry—I'll be back before your mother starts to miss me."
With his father absent, Itachi decided to modify his routine. The mornings would still be for physical exercise and taijutsu, but the afternoons and nights would become his personal laboratory. It was time to advance on ideas he had been gathering for weeks.
"If I can understand fire chakra and its flow, why not apply the same to electricity?" he murmured while drawing seals in the sand. He thought about the lightning jutsu he had seen and the physics behind electricity: magnetic fields, particle acceleration, interaction with other elements. "If I manage to channel electricity correctly and combine it with the seals… maybe I can manipulate particles, accelerate energy, and create effects that no conventional jutsu could achieve."
Itachi began to experiment with small currents of elemental chakra that mimicked electricity. He drew seals that concentrated the energy and then measured how it flowed through his hands, trying to modify the intensity and direction. Each failed attempt gave him new clues. Now he didn't need a conductor; he could form threads with chakra… it could be said that it was like working with a superconductor.
"Perhaps the secret isn't just in increasing power, but in controlling the frequency…" he whispered, recalling the absorption technique he had perfected.
Renji watched him, fascinated, though he still couldn't understand everything. "Are you going to make the sand glow or something?" he asked. "Not yet," Itachi replied with a smile. "This is just the first stage. But one day, you might see it."
With Fugaku at the front and Renji watching fascinated, Itachi gave himself over completely to his experiments. His first test: using chakra as a superconductor thread. He drew seals on the ground to guide the flow and concentrated his energy into a small thread of chakra that he could stretch and direct.
"If I can make it vibrate at the correct frequency…" he murmured, "maybe I can move an object with just the energy."
He placed a small piece of metal in front of the thread, adjusting the intensity of the chakra current. To his surprise, the metal began to move gently, attracted and repelled by the controlled energy. It was an elemental Gauss cannon, powered by chakra instead of conventional electricity.
He continued to experiment. He drew magnetic fields with seals, and with precise movements, he created a simple electric motor, where the chakra energy accelerated a metal rotor. He observed how the flow of energy could manipulate metallic objects at a distance, and how small adjustments to the chakra's frequency changed the speed and force of movement.
Renji couldn't hide his amazement. "It's moving on its own! It's like magic!" Itachi smiled, although he knew it wasn't magic: it was science and chakra working together.
He didn't stop there. He tried variations of the same principle: small energy generators, systems where chakra produced controlled electric fields, and even experiments with metal suspended in the air that moved following the polarity of the chakra threads. Each successful experiment reinforced the idea that electricity could be integrated into the ninja world through chakra.
At the end of the day, Itachi looked at his courtyard full of metal and drawn seals. "This… is barely the beginning," he whispered. "But now I know I can manipulate energy with precision. Everything that comes after will be a matter of control and creativity."
Renji applauded timidly, fascinated by the visual effects. "One day… you'll teach me how to make objects fly like your threads, right?" Itachi smiled. "Yes, but first, we have to understand energy. Then, anything is possible."