Naruto: I am Uchiha Shirou

Land of Grass, Konoha Camp

It had been over three months since the last Kushina incident.

Amid the sweltering summer heat, the frontline enjoyed a rare moment of leisure. Many shinobi lazed about in the camp during their shift breaks, finding ways to kill time.

In the hills behind the camp, near a small waterfall, three shadow clones of Uchiha Shirou sat cross-legged on the water's surface, each holding two black senbon. Sparks of lightning occasionally flickered between the senbon.

The real Uchiha Shirou stood before the waterfall, his right arm extended and his expression solemn. In his palm, visible and tangible chakra steadily gathered.

"Three months... My arm is sore and swollen, but I'm still just a little short!"

His face was tense with determination as he gritted his teeth, his trembling hand persisting through the strain.

The Rasengan—an A-rank jutsu. Even with a clear understanding of its training process, mastering it was no easy feat. It lived up to its reputation as an advanced technique.

Jutsu ranks weren't just based on power; they reflected a combination of training difficulty and combat effectiveness.

"Naruto mastered this jutsu after the Chūnin Exams. Back then, his chakra control and jutsu knowledge were inferior to mine. His biggest advantage was his immense chakra reserves. After all, this jutsu was derived from the Tailed Beast Bomb!"

Shirou's mind replayed everything he had studied about the Rasengan. Suddenly, inspiration struck, and a look of excitement spread across his face.

"If that's the case, then the greatest challenge of this jutsu lies in the amount of chakra—compressing and rotating an immense quantity while maintaining stable output!"

Dense chakra swirled in his palm, scorching his skin, but Shirou paid it no mind. His eyes shone with unwavering determination.

Poof!

Poof!

To test his new idea, Shirou released his shadow clones. With all his focus, a vivid blue sphere of chakra appeared in his palm in an instant.

"I... I did it!"

Seeing the chakra sphere in his hand, Shirou's face lit up with excitement. With a triumphant grin, he pressed the Rasengan against a rock in front of the waterfall.

In an instant—

BOOM!

The fearsome blue chakra sphere left a deep, circular crater in the rock.

"This brat... he did it!"

Tsunade, who had just arrived, was stunned by the sight of Shirou who had been obsessively training for three months.

"Three months! He developed an A-rank jutsu on his own!"

"I did it!"

Shirou's laughter echoed by the waterfall, though his joy was soon overtaken by pain as he clutched his aching arm.

"Hey, Shirou! Didn't I tell you not to overdo it?"

Tsunade's sharp reprimand snapped Shirou back to reality.

When he saw Tsunade, Shirou offered a sheepish smile, rubbing his trembling hand.

"Captain Tsunade, I already placed today's supply report on your desk."

"I'm not talking about that!"

Tsunade scowled and stepped onto the water, her red-painted toenails glinting as she approached him.

"How many times do I have to tell you about the dangers of using shadow clones for training?"

Faced with her scolding, Shirou obediently bowed his head and nodded. "Captain Tsunade, you mentioned that my curse-mark Kekkei Genka contains a unique chakra that enhances physical and mental recovery. As long as I manage the balance carefully, shadow clone training isn't dangerous. I've always used it to train chakra nature transformation, which primarily requires mental focus. The chakra, stamina, and mental energy consumption are minimal."

Shirou's compliant tone only deepened Tsunade's headache. Shirou was infuriatingly obedient when it came to administrative tasks, excelling in logistics and paperwork. But when it came to his obsessive training, no amount of warning seemed to matter—he'd smile and nod, then proceed as he pleased.

"Show me your arm."

With Tsunade's firm tone, Shirou obediently extended his arm. It wasn't the first time this scene had played out in the camp.

Several Konoha shinobi who witnessed the moment exchanged knowing glances. Rumors swirled among them: Tsunade had found herself a loyal little lover—and a Uchiha at that!

The cool sensation of Tsunade's medical ninjutsu eased the pain in Shirou's arm. His face relaxed into a satisfied smile as he looked up at her. "Thank you, Captain Tsunade."

Shadow clone training was a method many shinobi knew of, but it wasn't widely practiced due to the heavy mental toll it took. Overtraining could even result in death, making it impractical for most. Only a handful of individuals—or Jinchūriki—could use this method effectively.

"That jutsu you just used is incredibly dangerous! Its destructive power and difficulty make it a clear A-rank jutsu," Tsunade remarked, her gaze lingering on the crater left by the Rasengan.

Shirou nodded with a smile.

"This jutsu is powerful, but it demands a vast amount of chakra. Ordinary chūnin might only be able to use it once, making it nearly impossible for them to train with it."

He explained further, "Chakra levels determine training efficiency. Someone with high reserves can train advanced jutsu multiple times a day, while someone with low reserves might only manage once, drastically slowing progress."

"I'm fortunate to have awakened two Kekkei Genka, and my chakra reserves far exceed those of most Uchiha."

Shirou's proud smile drew a scoff from Tsunade.

"Lucky, huh? How about mentioning how Kekkei Genka tends to shorten lifespans?"

Her comment left Shirou speechless, though inwardly, he thought, With you as my healer, I'll recover completely in three years.

Outwardly, however, he simply laughed awkwardly, earning him a smug, victorious look from Tsunade.

"Shirou, it's great that you're driven, but why haven't you practiced the summoning jutsu I taught you?"

Shirou hesitated, scratching his head.

"I've been too busy..."

Tsunade raised an eyebrow knowingly.

"Or are you worried about what people will say about you?"

Before Shirou could answer, the rustling of leaves and chatter of two approaching shinobi interrupted them, drawing Tsunade's ire.