"Besides Yakushi Kabuto, there's also that Hiruko from the Naruto movie—his Chimera Technique produces a similar effect. Looking at it this way, both forbidden arts must share the same foundation: the art of cellular regeneration. Should I start studying medical ninjutsu too?"
As someone who had crossed over into this world—and a transmigrant who knew the Naruto series inside and out—Tahara Rokuro was well aware that the entire story of Naruto could basically be summed up as "two grandsons doing everything in their power to stop their uncle from reviving their grandmother."
Although the supernatural powers of this world came in countless forms, there was one underlying rule: the closer your bloodline was to Kaguya Ōtsutsuki, the stronger you were.
Before Kaguya's appearance, the most powerful being had been the Sage of Six Paths. After his death, that title passed to his two sons—Indra and Asura. As for the Sage's brother, Hamura Ōtsutsuki—he only appeared in the movie, so it was uncertain whether he even existed in this world.
"If this world is one ruled by bloodlines, then medical ninjutsu capable of merging bloodlines is power I must master. Especially for someone like me—a mixed-blood Uchiha—my natural potential alone can't compare to those protagonists. Even someone like 'the Dutiful Son' leaves me in the dust. So yeah—medical ninjutsu is a must-learn subject."
Rokuro had already crafted a detailed plan for his growth. Now, he added medical ninjutsu to it. Fortunately, his method of learning ninjutsu followed the logic of programming syntax—otherwise, even with the Scroll of Seals in hand, there was no way he could have learned everything. He might even have had to follow Orochimaru's path—master immortality first, then take eternity to study every ninjutsu in existence.
A month passed in the blink of an eye.
In that time, Rokuro relied on his "coder's liver" (his sheer work stamina) and the Nine-Tails' chakra. Not only did he successfully craft one hundred villa sealing scrolls, but he also completed the ninja tools Orochimaru had requested—tools engraved with the technique of cellular regeneration itself.
After delivering both commissions, Rokuro's family finances finally turned from deficit to surplus.
He had even hit a small milestone—earning a full hundred million!
Of course, a hundred million in the Naruto world didn't hold the same value as a hundred million RMB, but it still placed them among the wealthy class.
After all, that was equivalent to the price of three Asumas—a huge sum by any measure.
To celebrate, the family of three visited the Akimichi Clan's barbecue restaurant that day. They ordered the finest wagyū and ate to their hearts' content.
When they returned home, Rokuro called Uchiha Kei into his room and handed her a headband-like ornament.
"What's this? A gift? It's pitch black—ugly!"
Kei wrinkled her nose in disgust.
"This isn't a gift," Rokuro said, expression serious. "It could be a treasure that revitalizes the entire Uchiha clan. Just put it on and activate your Sharingan."
Kei already knew Rokuro could create ninja tools, though she had no idea how he did it. Once, she'd begged him to teach her sealing techniques, but after three days of lessons, she gave up entirely—the cryptic, oracle-bone-like symbols of sealing scripts made her dizzy just to look at.
Following Rokuro's instructions, she fastened the black headband and formed the seals, activating her single-tomoe Sharingan.
At the same time, Rokuro took out a tablet-like device—another ninja tool, paired with the headband.
As soon as Kei's eyes activated, the tablet glowed. Countless sealing formulas began to cascade across the screen. Kei took one glance and immediately lost interest—those squiggly lines gave her headaches.
"Are we done yet? I can't keep my eyes active for long," she complained.
"Just a bit longer—it's still parsing."
"Parsing? Parsing what? The structure of the Sharingan?"
"Not exactly." Rokuro's eyes were glued to the screen, code-like patterns flickering in his reflection.
"It's parsing the chakra that activates the Sharingan. You might not know this, but according to some Uchiha texts, our clan members typically awaken their Sharingan through intense emotional trauma—strong negative emotions."
Kei fell silent, remembering her own awakening.
She had opened her eyes only after hearing the news of her parents' deaths—just as Rokuro described.
"According to the Second Hokage, Senju Tobirama, the Uchiha are born with deep, passionate hearts. Their love burns intensely—and when that love is lost, the brain generates a special kind of chakra. When that chakra merges with the eyes, it gives birth to the Sharingan, also known as the Eye that Reflects the Heart."
Rokuro gestured toward the headband on her forehead.
"Whatever Tobirama's methods were, as a master of ninjutsu invention, his words hold weight. So my goal now is to analyze that special chakra. Once I successfully parse its structure, I can synthesize it with sealing scripts—meaning anyone could awaken the Sharingan without experiencing tragic loss."
Kei's eyes widened in disbelief. "Rokuro, are you saying that if you succeed, not only you but other Uchiha could awaken their eyes the same way?"
Rokuro nodded.
"Exactly. And not just awaken them. You've heard the rumors—our eyes grow stronger the more we suffer. If that's true, then that special chakra doesn't just awaken the Sharingan—it can enhance it. Once I've parsed it, our clan could achieve what the Hyūga have: nearly universal eye activation."
Kei's heartbeat quickened.
"You mean… even evolving beyond the three-tomoe Sharingan—to the Mangekyō?"
Rokuro smiled faintly.
"That's right. Above the three tomoe lies the Mangekyō Sharingan. Beyond that, the Eternal Mangekyō. And even above that—an eye of legend. But all of that starts here—with decoding this chakra."
Her pulse raced. The once incomprehensible runes now looked almost endearing.
Finally, under their gaze, the flowing symbols on the tablet froze—stabilizing into a single formula composed of twelve runic seals.
Rokuro called it a Chakra Molecular Formula, each rune representing a "chakra atom."
"Did it work?" Kei asked, unable to read the symbols.
Rokuro didn't answer right away. Instead, he took out a sheet of chakra paper and began transcribing the formula onto it, his chakra-infused brush gliding across in swift strokes.
When he finished, he pressed the paper to his forehead and channeled chakra through it.
The chakra transformed according to the formula—reshaped into a new property—then flowed into his eyes.
A sudden heat flooded his vision; his eyes tingled and burned.
Kei gasped.
"Rokuro… your eyes—!"
In that instant, Tahara Rokuro's eyes had turned scarlet, with a single tomoe spinning within each—
the Sharingan had awakened.