What Renji didn't know was that all of his actions had just been closely observed—by none other than an old man with a rather questionable hobby of "peeping."
Through his crystal ball, the Third Hokage, Hiruzen Sarutobi, had been monitoring the situation. At first, he had only been checking on young Hinata Hyūga, who had recently run away from home. Ever since the tragedy when Hinata was kidnapped years ago and her uncle Hyūga Hizashi lost his life protecting her, Hiruzen had made it a habit to occasionally keep watch over her—if such an incident were to repeat itself, the Hyūga clan would rise in open revolt.
But to his surprise, what he ended up seeing was the sudden appearance—and actions—of Uchiha Renji.
The next morning, Renji once again went to Training Ground Seven to practice. Though he could already release the Fire Style: Great Fireball Jutsu, its power was far from satisfactory. For now, all he could do was keep training relentlessly. By the time he stopped, the sun was already high overhead.
"Renji, where are Itachi and Shisui?"
It was Uchiha Izumi, walking over with a lunch basket in her hands. She had shown up again, as she often did.
"Ah, Izumi-nee," Renji answered, tilting his head. "Big Brother Itachi went on a mission, and I think Big Brother Shisui had something to do as well. They said they'll both be back the day after tomorrow."
Seeing her expression, Renji couldn't help but feel puzzled. After all, even he knew about their schedules—so how could Izumi not?
"Oh…" Izumi's tone carried a faint disappointment.
Renji squinted at her and suddenly asked with a mischievous smirk, "Izumi-nee, you like Itachi, don't you?"
Her face turned bright red. "Wh–what are you—!"
"Well, if you didn't like him, why would you keep coming here every single day?" Renji teased. "I bet you met him back in the Academy, right? Honestly, Izumi-nee, if you really like Itachi, why not just tell him? You know how he is—Big Brother Itachi and Big Brother Shisui are both pretty dense. If you don't say anything, he'll never notice."
Being confronted so directly by a four-year-old made Izumi's face flush even deeper. She glanced around quickly to make sure no one else had heard him, then leaned closer, whispering hurriedly, "Renji… you didn't tell anyone else about this, did you?"
"Nope! Just Shisui-niisan. Otherwise, whenever you come looking for Itachi, he'd always stick around and be the third wheel." Renji grinned devilishly. "Oh, and by the way, Itachi doesn't really like grilled meat that much. He actually prefers dango and natto."
Izumi stared at him, completely thrown off. How does this little brat even know that much…?
Finally, she just gave up, sat down beside him, and unpacked the food. "Since Itachi isn't here, I guess you get to eat it instead. So? What were you doing out here anyway?"
"Training ninjutsu, of course! Shisui-niisan taught me the Great Fireball Technique. He said he'll test me in three days. I can release a fireball now, but it's still way too small. Look—"
Renji inhaled, clasped his hands into seals, and shouted:
"Katon! Gōkakyū no Jutsu!"
A burst of flame erupted from his mouth. It was definitely larger than before—around the size of his head—but still not the massive fireball the jutsu was meant to produce.
"Eh…?" Izumi was stunned. At the Academy, all they ever taught at that stage were the basic Three Body Techniques—Transformation, Substitution, and Clone. A C-rank jutsu like the Great Fireball was well beyond that. Even many genin struggled to master it. Yet here was a four-year-old boy releasing it, albeit imperfectly.
This kid really is something else… At his age, even an incomplete version of a C-rank ninjutsu is extraordinary.
"Renji, what's happening is simple—you're not using enough chakra," Izumi explained carefully. "Either you don't have enough chakra overall, or you're channeling too little of it into the technique. That's why the fireball isn't forming properly. But honestly, for your age—"
She was about to reassure him that what he had already achieved was remarkable, but Renji cut her off the moment he heard the word "chakra."
"So it's just a matter of output? Got it!"
Without hesitation, he refocused, pushed more chakra through his network, and wove the hand seals again.
"Katon! Gōkakyū no Jutsu!"
This time, an enormous fireball roared into existence—flames swirling violently as the completed jutsu burst forth in its full, perfected form.