Uchiha Seiichi

Konoha Year 38.

Uchiha Fugaku, who had just succeeded as head of the Uchiha Clan, had gained another identity.

A father!

He and Uchiha Mikoto had a child of their own.

A boy.

The instant the newborn opened his eyes, a vivid flash of red met Fugaku's gaze.

His Sharingan had awakened at birth!

Overjoyed, Uchiha Fugaku regarded the child as the future hope of the Uchiha Clan and named him Seiichi, Uchiha Seiichi.

Meanwhile, Seiichi was rather bewildered.

Hadn't he already died?

He had died just before the development of the targeted drug succeeded.

Five minutes.

He had been just five minutes short.

In his previous life, Seiichi had been born into a wealthy family, one with power, influence, and plenty of members.

People always talked about giving their children a head start.

He could say he had been born right on the winners' podium.

He had fine features and a dignified appearance.

His IQ exceeded 140.

He was cheerful, his family was harmonious, and the brothers treated one another with affection and respect.

At nine, he had been admitted to the Young Gifted Class at the nation's most prestigious university.

It could be said that by nine, he already had everything most ordinary people dreamed of their entire lives.

But things did not go as he wished.

When he was ten, he fell on the university's sports field, and the resulting examination revealed that he had a terminal illness involving muscular atrophy.

Still, he neither lost heart nor gave up on himself.

He chose to withdraw from school.

At home, he taught himself biology and medical theory.

At first, the doctors declared he would not live to adulthood. Later, they changed that to twenty-two, then twenty-five, then thirty.

Time and again, he successfully prolonged his own life.

Finally, under his leadership, a targeted drug for treating muscular atrophy was successfully developed.

But his life ended at thirty-four.

It ended five minutes before the new drug was successfully synthesized.

None of that mattered anymore, though.

Seiichi only wanted to know what was going on with this infant body of his.

Rebirth?

Transmigration?

In his previous life, when the pressure became too much, Seiichi had read plenty of webnovels and watched anime to unwind.

But weren't those things just made up for fun?

This was happening for real?

As his thoughts churned, his eyes felt a little hot. He forced his somewhat heavy eyelids open and saw a tall, fierce-looking, red-eyed man staring intently at him.

His infant body could not support much thinking.

After a brief glance, he promptly fell into a deep sleep.

Time flew.

In the blink of an eye, it was Konoha Year 43.

The baby who had once struggled even to open his eyes had become an exquisitely cute five-year-old boy.

He had inherited the Uchiha Clan's handsome features and was even more outstanding.

His hair was tied in a little bun, with a stray lock falling over his forehead. Handsome and good-looking, he looked neat and sharp.

"Father, calm down. Mother and my little brother will both be fine."

Watching Uchiha Fugaku pace back and forth around the courtyard was making Seiichi a little dizzy.

"You're still little. You don't understand! Wait, why did you say little brother?"

"Intuition!"

"Congratulations, Clan Head! Mother and son are both safe!"

Fugaku was overjoyed at the news.

The moment he was allowed inside, he rushed in.

Seiichi followed at an unhurried pace.

"Mikoto, look. This is our second son."

"He's a little ugly."

Seiichi stood on tiptoe for a look, and his words made everyone in the room laugh.

"All newborns look like this. He'll grow into his looks after a while. No one in our Uchiha Clan is ugly, man or woman."

Seiichi thought about it, and that did seem true. At least, none of the named Uchiha Clan members he remembered were ugly, and they looked even cooler after awakening their Sharingan.

They were nothing like the Hyuga Clan.

Apart from Hinata and her sister, and the cousins Neji and Hinata, none of them were good-looking, and they looked even uglier after activating their Byakugan! Even those three good-looking ones became ugly!

"Itachi. Your name will be Uchiha Itachi."

Everyone present was smiling, except Seiichi.

Because no one but him knew what the name "Itachi" represented.

Although Itachi in the original story had been thoroughly manipulated into doing many unforgivable things.

From Seiichi's perspective, however, he could understand it.

Itachi had barely received any proper schooling to begin with, and in the end, he had chosen to graduate early. His exams had tested combat ability, too.

In Seiichi's previous world, he would have been a semiliterate elementary school dropout. It was good enough that he could read. Could anyone really expect him to have profound insights?

Impossible.

So, with a simple-minded, semiliterate boy like that being brainwashed from the age of a few years old, it would have been hard for him not to end up led astray.

As far as Seiichi was concerned, it was still early. There was time for everything.

This little brother was going to be his useful pawn. He had decided, and that was final!

Seiichi had regularly asked Fugaku to find him plenty of information on the Shinobi World's Kekkei Genkai, and he had also examined the Uchiha Clan's ancestral records.

In doing so, he had gradually made some new discoveries.

The Uchiha Clan's bloodline was incomplete, or rather, flawed!

He worked backward from the final outcomes he knew.

First, the Uchiha Clan required intense emotional stimulation to awaken their Sharingan. Awakening the Mangekyō Sharingan required extreme emotional stimulation.

Second, excessive use of the Mangekyō Sharingan could easily lead to blindness.

Third, creating the Eternal Mangekyō Sharingan required combining the Mangekyō Sharingan of two brothers.

Fourth, combining the ultimate yin release represented by the Eternal Mangekyō Sharingan with the ultimate yang release represented by Hashirama Senju's sage body could create the true eyes of a sage-the Rinnegan.

Working backward from the data above.

Awakening the Sharingan, including the Mangekyō Sharingan, showed that its awakening was linked to spiritual power, or yin release.

But the Uchiha Clan had no method for training yin release, so they could only resort to crude emotional stimulation.

The advantage of this method was that it was simple to carry out.

The disadvantage was a drastic personality change after awakening, with a tendency toward madness!

Yet the Hyuga Clan, who also originated from the Ōtsutsuki Clan and were likewise a Konoha clan with ocular techniques, had none of these complications.

The Byakugan's upper limit was also very high. The Tenseigan and the Rinnegan were on the same level.

But the Byakugan had none of these convoluted complications.

Both its awakening and its use were stable, without any hidden risks.

That was very wrong.

"Emotional stimulation to awaken them, blindness, replacing the eyes... wait, I think I've got it!"

Sitting on the steps of the courtyard veranda, Seiichi kept feeling that there was some crucial clue he had failed to grasp.

But he simply could not think of it.

Not until he saw a piece of fruit fall from a tree in the courtyard and crush a little insect to death.

He finally realized what clue he had been overlooking all along.

Seiichi took out a sheet of paper and wrote down his analysis in the small seal script of his previous life.

Hyuga: Byakugan → Tenseigan. That was it.

Uchiha: one-tomoe Sharingan → two-tomoe Sharingan → Three-Tomoe Sharingan → Mangekyō Sharingan → eternal Mangekyō Sharingan → Rinnegan.

As Seiichi remembered it, the Sage of Six Paths had never had a so-called Mangekyō Sharingan.

He had gone straight from the Three-Tomoe Sharingan to the Rinnegan.

But the Sage of Six Paths' son had possessed the Mangekyō Sharingan.

Although the evolution from Byakugan to Tenseigan involved only two stages, the gulf between them was like the heavens crashing down. From beginning to end, not a single person had successfully evolved their own Byakugan into the Tenseigan.