The Rinnegan and the Tenseigan

Sasuke snapped, his embarrassment turning to anger. "So I don't know! I haven't even graduated from the Ninja Academy yet!"

"Heh! The Rinnegan, Byakugan, and Sharingan are three hereditary eye techniques collectively known as the Three Great Dōjutsu, and you don't even know that? That's hardly the standard I'd expect from the heir to one of Konoha's great clans. You should read more books on the subject." Neji mocked him without mercy, then continued, "The Rinnegan was the Sage of Six Paths' eyes. Those eyes possessed the power to bring peace to a world torn by war!"

"So you're saying that combining the two opposing powers of yin and yang mentioned on the Stone Tablet would awaken the Sage of Six Paths' eyes—the Rinnegan?" Sasuke could no longer stay calm. His breathing quickened.

"That's right. That's what I deciphered." Neji nodded.

By now, Sasuke believed him to some extent, for one simple reason: Neji had mentioned the Uchiha Clan's Stone Tablet.

He had never told anyone about that Stone Tablet. Since Neji had accurately described it, that meant the Hyuga Clan really did have a Stone Tablet of its own.

Sasuke thought for a moment, then asked, "Reincarnation corresponds to the Rinnegan, so does rebirth correspond to the Tenseigan?"

Neji nodded. "Exactly. Since reincarnation corresponds to the Rinnegan, rebirth should correspond to the Tenseigan."

"The Rinnegan, the Tenseigan..." Sasuke murmured. Suddenly, he said, "If the Rinnegan was the Sage of Six Paths' eyes, could the Tenseigan have been his younger brother's eyes?"

Neji looked pleased. "Exactly. If the Sharingan's ultimate form is the Rinnegan, then the Byakugan's ultimate form is the Tenseigan!"

"So that's how it works..." Sasuke muttered to himself.

After puzzling over it on his own for a while, Sasuke seemed to think of something. "Neji, what power does the Rinnegan actually have for it to be called a divine power capable of bringing peace to a war-torn world?"

Neji said nothing. Instead, he opened the study window and pointed at the bright moon already visible in the twilight sky.

"What do you mean?" Sasuke walked over to the window, confused.

"The Sage of Six Paths once used the Rinnegan's power to create the moon, then used that moon to seal away the World-Destroying Demon!" Neji said calmly.

Neji's matter-of-fact words thundered through Sasuke's heart.

Sasuke stared at the bright moon in disbelief, feeling his entire understanding of the world shaken. What incredible divine power!

If I had the Rinnegan too... Itachi, just you wait! The thought set Sasuke's heart ablaze.

He soon collected himself and said firmly, "Count me in on this!"

Sasuke had been completely won over by Neji. In the end, he was only an eleven-year-old child.

Neji had intended to bring him aboard anyway. Where else would he get the funding? "I never intended to leave you out. I'll need your help to awaken the Tenseigan."

"You need my help? What can I do?" Sasuke did not understand.

"Of course I need you," Neji explained. "You're the yin half of yin-yang polarity!"

Sasuke's young mind raced. "No one can rival our Uchiha Clan's genjutsu, so we could certainly be considered the embodiment of yin. If the Uchiha Clan represents the yin half of yin-yang polarity, then could the Senju Clan represent yang?"

"Legend has it that the First Hokage, Hashirama Senju, possessed a hereditary ability called Wood Release that transformed chakra into a source of life, allowing him to make trees fight. Looking at it now, that certainly fits the idea of yang."

"But the Senju Clan only exists in name now. No one inherited the First Hokage's hereditary ability..." Sasuke looked at Neji.

He already considered himself a partner in this venture. In fact, that was exactly what he was.

Neji patted Sasuke's shoulder. "There's still the Uzumaki Clan! Both the Uzumaki Clan and the Senju Clan represent yang. Members of that clan are born with enormous amounts of chakra. Just look at Naruto Uzumaki in your class. That guy has so much energy it's ridiculous. He hardly seems human."

"Now that you mention it, that does seem to fit!" Sasuke thought of Naruto Uzumaki.

That guy really did have a ridiculous amount of energy. Even after playing pranks every day, he still had enough left to pick fights with Sasuke, who was thoroughly sick of it.

"Naruto Uzumaki, huh? He certainly has a lot of vitality." Sasuke nodded in agreement.

"But that raises a question. How do we fuse yin and yang together?" Sasuke asked a crucial question.

"How? It's simple! Just replace one of your arms with Naruto Uzumaki's!" Neji's words sent a chill through Sasuke's heart.

"Well..." Sasuke hesitated. "Isn't that a bad idea? If we each take one of his arms, won't Naruto be left without any?"

Neji was speechless. "That's why I had Cat Granny get the Cloning Facility and the relevant technology!"

Neji looked at him as though he were an idiot, leaving Sasuke deeply embarrassed.

"Hmph!" Sasuke snorted. "How was I supposed to know about your shady methods?"

Neji merely shrugged, then looked at him. "The next part is up to you. Find a way to get some tissue samples from Naruto Uzumaki."

Sasuke thought for a moment. "That'll be easy. I'll just trick him into coming to the Training Ground for a spar. That dead last, Naruto Uzumaki, is always trying to compete with me."

"You'd better have a convincing story ready," Neji said gravely. "There's more to Naruto Uzumaki's identity than you think."

"Does the village place that much importance on the Uzumaki Clan?" Sasuke asked, puzzled.

In his view, even being a member of the Uzumaki Clan would not warrant the village assigning people to watch over Naruto all day. Even he, a member of the Uchiha Clan, did not receive that treatment.

"His father was the Fourth Hokage!" Neji dropped the bombshell without warning.

There was no harm in telling Sasuke this. He had an even bigger revelation to share later anyway, so this would prepare him for it.

Sasuke's eyes widened. "What? That dead last is the Fourth Hokage's son?"

Sasuke thought that sounded ridiculous. The Fourth Hokage was said to have been an unrivaled genius. How could his child be dead last?

Besides, how should he put it? Sasuke had never seen any redeeming qualities in Naruto. He failed at everything he tried to learn and spent his days skipping class and causing trouble.

"Then why is he treated like that? Practically everyone hates him." Sasuke could not make sense of it.

Rather than answer directly, Neji asked, "Do you know about tailed beasts?"

Sasuke nodded. "Legend has it that there are nine tailed beasts in the world, and the Nine-Tails is the strongest. Ten years ago, the Nine-Tails attacked Konoha. They say the Fourth Hokage died sealing away the legendary Nine-Tails."

"And that Nine-Tails is now sealed inside Naruto Uzumaki's body!" Neji said evenly.

Sasuke jumped in shock. "The Fourth Hokage sealed the Nine-Tails inside his own child? Then why is that dead last still treated like this?"

Neji sneered. "That's what you don't understand. People like Naruto Uzumaki, who have tailed beasts sealed inside them, are generally called jinchūriki. Jinchūriki are their villages' strongest weapons."

"Weapons?!" Sasuke felt that there was something absurd about this village.

"Exactly. Jinchūriki have been weapons ever since they first came into existence." Neji nodded, then asked, "How do you think you'd control a weapon with a mind of its own?"

"With something like your Hyuga Clan's Caged Bird Seal?" Sasuke asked uncertainly.