The treatment continued for quite some time. By the time the green light fading from Tsunade's fingertips finally vanished, the gruesome, terrifying wound on Shinichi's right arm was completely gone.
The newly formed skin carried a faint pinkish hue, and the muscle fibers had been restored to their original state. While the arm was still weak and powerless—requiring a long period of rest to regain full functionality—that sensation of continuous, destructive erosion and the bizarre nature of the injury had been completely eradicated.
"The toxins in the wound have been cleared, and the foundational repairs are done. The rest is up to your own recovery. With your constitution, you should be able to move it around after lying in bed for half a month."
Tsunade withdrew her hands. Her face was still somewhat pale, her bangs plastered to her forehead with sweat, but her eyes were far clearer than when she had arrived.
She delivered her instructions without even looking at Shinichi. "But remember: absolutely no high-intensity ninjutsu or taijutsu training for a month. Otherwise, you'll leave hidden damage that'll make you suffer every time it rains."
With that, she turned and walked straight toward the door.
Pulling it open, Tsunade paused for a moment when she saw the Third Hokage and the Ape Demon King standing outside.
"Old man," she greeted him. Her tone was flat, completely devoid of emotion.
"Thank you for your hard work, Tsunade," the Third said gently, his concerned gaze lingering on her pale face for a second.
Tsunade avoided his eyes. She simply waved a hand and walked briskly down the hallway, her back straight and her pace hurried, as if desperate to leave the place.
The Third watched her go until her long blonde hair disappeared around the corner. Only then did he retract his gaze and look back inside the ward.
On the bed, Shinichi was lightly testing the movement of his newly reattached right fingers. His face betrayed no particular emotion—neither the relief of having survived a disaster nor anxiety over his injury. He was entirely too calm for a boy who had just recovered from severe trauma.
"How do you feel, Shinichi?" the Third asked in a steady voice as he walked into the room.
"Much better, Lord Hokage. Thanks to Lady Tsunade," Shinichi replied politely and respectfully.
The Third nodded and sat down in the chair beside the bed. He pondered for a moment before speaking slowly.
"The Ape Demon King has given me a detailed report regarding this new jutsu of yours, the Great Flame Rasengan. Its power is astonishing, but the risks are equally extreme. Until you find a way to fully master it—or eliminate the backlash—I forbid you from using it casually again. This is not a suggestion. It is an order! Your future is far more important than an incomplete jutsu. Do you understand?"
Shinichi met the Third's stern gaze, stayed silent for a few seconds, and then slowly nodded. "Yes. I understand, Lord Hokage."
There was no hesitation in his obedience, yet the Third saw a flicker of an unextinguished flame deep within those calm eyes.
He knew that this boy's "understanding" might merely be a temporary hibernation.
After offering a few more words of advice to rest and recover, the Third stood up and left. As Hokage, he simply had too much paperwork waiting for him.
Silence returned to the ward. Shinichi leaned back against the headboard, staring out the window at the falling snow, lost in his own thoughts.
---
Half a Month Later, Deep Winter.
Snow still blanketed Konoha's Fourth Training Ground, the air crisp and freezing.
The Ape Demon King stood with his arms crossed, an expression of utter helplessness on his face as he watched the black-haired boy stretching in the center of the field, his breathing already steady.
Beside him stood the Third Hokage, Sarutobi Hiruzen, draped in his Hokage robes. He watched the boy quietly, his gaze warm yet appraising.
Shinichi's recovery speed had far surpassed Tsunade's expectations. But the moment his injury had stabilized, he had couldn't wait to throw himself right back into training.
He had started with a carefully controlled sparring session against the Ape Demon King, smoothly transitioning between taijutsu and ninjutsu. Then, the boy had actually started considering how to perfect the Great Flame Rasengan again.
Knowing full well the dangerous backlash of that jutsu and unable to talk the kid out of it, the Ape Demon King had simply invited the Third Hokage—who happened to have a rare moment of downtime—to come observe.
With the Third present, at least they had a safety net.
"Shinichi," the Third Hokage called out as the boy approached.
He didn't issue direct orders or reprimands. Instead, like a mentor guiding a disciple's thoughts, he asked peacefully, "You're so eager to try again. Have you thought of a way to solve the backlash problem?"
"Yes, Lord Third," Shinichi bowed respectfully before nodding frankly. "Over the past half-month, I've repeatedly thought back to the details of how I got hurt and summarized the cause. The Rasengan itself is a highly compressed, violently spinning sphere of chakra. By its very nature, it's unstable."
"The Great Flame Rasengan forcibly injects notoriously violent Fire-nature chakra into it. The combination multiplies the power, but it also makes the internal energy insanely chaotic. In the instant it hits a target and the energy releases, that chaotic feedback travels straight back into the arm maintaining the chakra's shape, causing severe corrosion and tearing."
He paused for a second before continuing. "So, the simplest solution is this: don't let it detonate in my hand. If I can throw it safely—like a kunai or shuriken—and have it explode far away from me, the backlash problem is solved."
The Third Hokage nodded slightly. "Throwing it to avoid direct contact damage—that direction is indeed correct. It is one of the standard approaches to solving the backlash of close-range, explosive ninjutsu."
However, he immediately pivoted, pointing out the core difficulty. "But Shinichi, the problem lies in safely throwing it. A normal Rasengan struggles to maintain its shape once it leaves the hand, let alone the highly unstable Great Flame Rasengan injected with volatile Fire-nature chakra. It's like a lit stick of dynamite with a hair-trigger fuse. You need to focus entirely just to keep it from blowing up while you're holding it. The moment it leaves your hand and loses your continuous chakra control and shape manipulation, it will lose stability and detonate on the spot."
The Ape Demon King chimed in with a deep voice, "Hiruzen is right. Kid, the idea is good, but pulling it off is too hard. The moment that thing leaves your hand, it's just a firecracker waiting to go off. It won't fly far at all."
"You're right, Lord Third, Senior Ape Demon King. I've repeatedly analyzed that exact problem."
Faced with the core dilemma pointed out by the Third and the summon, Shinichi showed no signs of discouragement or confusion. Instead, he nodded.
"Because of that, I came up with another approach. The Great Flame Rasengan's backlash stems from the combination of extreme compression, rotation, and volatile Fire-nature chakra, making the jutsu incredibly hard to control and highly unstable upon detonation. So, what if we take a step back? What if we keep the Rasengan's core advantage of rapid, high-density chakra condensation, but appropriately lower the degree of compression, while completely removing the rotation that exacerbates the instability?"
"Like this!"
Before he even finished speaking, Shinichi raised his right hand, spreading his fingers slightly.
There were no complex hand seals, not even any obvious, violent fluctuations of chakra. A fierce, condensed sphere of crimson flame suddenly materialized in his palm, as if tamed by an invisible force!
This flame wasn't expanding outward like a typical Fire Release jutsu, nor was it violently spinning and compressed to the absolute limit like the Great Flame Rasengan.
It looked more like a highly concentrated core of fire—stripped of any excess volatility and appearing almost solid—burning quietly while emitting waves of scorching, yet perfectly stable, energy.