Mangekyo

"They're like major port cities along a river. Chakra is refined from every cell in the body, initially like countless small streams converging into these main meridian rivers."

Little Kosuke extended his index finger and traced a small circle on his own body. "Forget the existing chakra flow routes for now. This small circle is the most basic circulation, which I call the 'Lesser Heavenly Circulation.'"

"Listen carefully. This is simple, but very important!"

"And don't try it, understand?"

"I don't know what the consequences or benefits would be either. In short, don't attempt it until it's been tested!"

Afraid the others might secretly try it, Kosuke had to solemnly and sternly repeat his warning.

Seeing everyone nod to show they understood the gravity of the matter, he continued.

He pointed below his navel. "This is the Dantian, the gathering place of chakra. You can feel it carefully—it's warm."

Kosuke didn't stop. He turned and pointed at his spine. "This is the Du Meridian. Chakra starts from the Dantian, flows upward along it, passing through the lower back, the center of the back, the back of the neck, all the way to the crown of the head."

"This is the Ren Meridian. After reaching the crown, chakra then flows down the front of your body—from the forehead, nose, mouth, throat, chest, navel—and finally returns to the lower Dantian."

After speaking, Kosuke traced another circle with his hand. "This circuit—starting from the lower Dantian, going up along the back, then down along the front, back to the lower Dantian—is a complete 'Lesser Heavenly Circulation' cycle."

Kosuke paused, picked up his cup, and drank it all in one gulp. Then, seeing Izuna and the others frowning with their eyes tightly shut, he said in a deep voice, "Don't overthink it. There's plenty of time to understand later. For now, let's move on to the 'Greater Heavenly Circulation.'"

Just then, the courtyard barrier suddenly rippled.

Aoba shook her groggy head. Her remaining Sharingan instantly activated, and through the courtyard wall, she saw it was Madara's clone returning from home.

At that moment, the Earth Clone was standing outside the barrier, carrying a huge burlap sack on its shoulder and patting it incessantly.

"How did a barrier go up here in just one trip out?"

Aoba withdrew the Sharingan from her eyes, channeled chakra to open an opening in the barrier for the clone to enter.

"Aunt Aoba, is it my Earth Clone back?"

"Yes. It seems Little Kosuke's blank paper has been found."

"Oh? Found it?" Kosuke put down his hands and looked in surprise at the "Madara" stepping into the courtyard.

"Put it in my room for me."

Hearing this, Madara's Earth Clone walked straight past the table in the courtyard toward the room Kosuke had pointed at.

"Alright, let's continue."

Kosuke's gaze grew deeper. "The Lesser Heavenly Circulation lays the foundation—it's about managing the cycle inside your 'home.' The Greater Heavenly Circulation, on the other hand, connects your 'home,' meaning your body, to the vast outside world!"

Under the bewildered gazes of the others, he suddenly spread his arms as if embracing the sky.

"The Greater Heavenly Circulation builds on a stable Lesser Heavenly Circulation. It lets chakra flow from the main meridian 'rivers' into finer tributaries—the tiny meridians that run through your limbs and bones! More importantly, it opens the 'windows' between the body and the outside world—those chakra points!"

As he spoke, Kosuke swapped the paper in his hands and picked up the diagram that had made the others dizzy earlier.

His small finger slid across it without stopping.

"Once our Lesser Heavenly Circulation is stable, chakra will spread like tree roots from the Ren and Du Meridians in all directions—flowing into your arms, fingers, legs, feet, toes..."

"I speculate this can greatly enhance fine chakra control, allowing chakra to reach any point in the body as flexibly as an arm."

At this, Aoba's eyelashes fluttered slightly. She suddenly thought of the precise control required for Medical Ninjutsu.

"Then..." Kosuke's voice interrupted her train of thought. "The most critical step: through specific training and intent, try to have those important 'ports' on your body's surface—the acupoints—'open' slightly as you breathe!"

"When you inhale, imagine not just breathing in air, but also the 'Natural Energy' that exists everywhere in nature. When you exhale, expel the 'turbid energy' generated after internal circulation."

"What are those important 'ports'?"

Izuna's puzzled voice suddenly rang out.

"You... understood?" Kosuke stopped his explanation, looking at the questioning Izuna with joy and excitement.

His voice immediately drew the attention of Aoba, Madara, and Mina.

They looked enviously at the hesitant Izuna, muttering inwardly.

"Could it be that everything Izuna did before was an act? That he's actually very smart?"

But that thought shattered the moment Izuna spoke next.

"No... I don't understand."

"Then why did you ask?" Kosuke said irritably. He had thought the other had actually understood under his earnest teaching.

Instead, Izuna had pulled a fast one.

The envious looks from Madara and the others instantly turned to disdain.

But Kosuke patiently explained anyway: "The most important ones are the Laogong Acupoint in the palms and the Yongquan Acupoint in the soles of the feet."

After a perfunctory reply, he continued where he had left off. "This way, chakra no longer relies solely on internal refinement. It becomes flowing, living water. The internal cycle nourishes and strengthens the self; the external cycle expels the old and takes in the new, subtly resonating with heaven and earth."

At this point, Kosuke suddenly stopped and added, "Note: you're inhaling Natural Energy, not chakra! Mixing the two would cause trouble!"

Having said that, he ignored everyone's reactions and finished his final words in one breath.

"Internal energy recovers faster, its quality becomes purer, endurance grows stronger, and perception becomes sharper! It's like standing in the wind—you don't just feel the wind, you can sense the power contained within it!"

To avoid misleading everyone, he simply changed the word "chakra" to "energy" in the later parts.

As soon as he finished speaking, Kosuke quickly sat down and poured himself a drink.

Moments later, everyone's pupils sharply contracted from extreme shock.

"According to you, we can absorb external energy to replenish ourselves while fighting?!"

"Doesn't that mean we get stronger the longer we fight?"

Kosuke slowly shook his head: "That's impossible. Have you ever heard of Going Berserk..."

Just then, Aoba's expression suddenly became agitated as memories surfaced in her mind—her husband who died three years ago, her own stubbornness, and now Kosuke and Mina striving to grow stronger.

Her heart clenched sharply, and a surge of intense self-blame and grief rushed to her brain.

The Three Tomoe Sharingan in her eyes abruptly manifested and began spinning at high speed.

The afterimages of the tomoe grew increasingly blurred and illusory; glancing at them, they seemed to slowly melt and reform.

At the same time, her Dojutsu radiated outward.

Mina, not understanding what was happening, saw her mother in such pain and wanted to step forward to comfort her.

But Madara, quick as lightning, reached out and stopped her.

Feeling the powerful Dojutsu spilling out, he said in a low voice: "Don't disturb Aunt Aoba!"

Mina looked back at Madara in confusion, then turned her gaze to her younger brother Kosuke.

Kosuke gently shook his head, signaling not to disturb their mother, and only then did she suppress her overwhelming anxiety and quiet down.

If she hadn't been stubborn back then and taken that undercover mission, and if she hadn't given birth to Kosuke, with her help, would her husband, Uchiha Gen, still be alive?

Would Mina not be so desperate for power now?

At this thought, the special Yin Release chakra secreted in Aoba's brain grew increasingly intense.

The high-speed spinning Sharingan suddenly reversed its rotation.

The three tomoe twisted, melted, and reformed in the crimson light, forming an intricate pattern.

In Aoba's right eye, an inverted blood-red lotus appeared, with chain patterns interwoven between the petals. As the Mangekyo's Dojutsu surged, it bloomed with a red light hot enough to scorch the soul.

The moment the Mangekyo took shape, an invisible pressure like a solid force enveloped the courtyard.

Kosuke felt as if his chest were being squeezed by an invisible giant hand. The surrounding air suddenly solidified, and even struggling to breathe became a luxury.

At that moment, the four children's faces turned purple, and painful whimpers escaped their throats.

Sensing something amiss in an instant, Aoba abruptly covered her right eye and deactivated the Mangekyo.

The crimson light of the Mangekyo flickered between her fingers, and the dense Dojutsu dissipated like an ebbing tide.

Cough, cough, cough, cough~

Kosuke and the others collapsed onto the table, gasping heavily, greedily breathing in the sweet air.

After about the time it takes to drink a few cups of tea, Madara, two years older, was the first to recover, though he was still panting heavily.

He straightened his back again, his eyes filled with ecstasy, staring intently at Aoba's covered right eye. The envy in his gaze almost overflowed.

"Aunt Aoba, your eyes..."

Aoba wiped away the blood trickling from the corner of her eye, struggling to calm the surging emotions within her.

When she opened her eyes again, the blurriness caused by overexertion had completely dissipated, and her vision was crystal clear.

Hearing Madara's question, Aoba slowly nodded but said nothing more.

By then, Kosuke and Izuna had finally fully recovered from the suffocating sensation.

Kosuke immediately grabbed the juice on the table and gulped it down.

"Ha~ Refreshing!"