Secrets Of The Sharingan

The problem with promises is that one party always remembers them and make sure the other keep their word. Five years ago, Jun had promised Sasuke to tell him all about the Sharingan as soon as he awakened his Dojutsu. Sasuke hadn't brought up the subject since, but Jun knew he hadn't forgotten. So after returning from his last mission, it was only a matter of time before Sasuke came asking for answers.

Jun had hesitated between taking Sasuke aside to reveal what he knew, or announcing it to everyone in the family. Izumi already knew a lot of things but not everything. Kazuma had no Dojutsu currently, but the Sharingan was part of his legacy. And there was the possibility he may awaken it one day, so he deserved to know as well. As for Neji and Karin, they were part of the family. Moreover, Jun and the other Uchihas knew a lot about their family affairs. It was only fair they knew some secrets of the Uchihas. The main reason was that Jun trusted them.

The Uchiha clan leader waited for the whole family to gather together. It wasn't easy; they all had busy schedules. But three days after Sasuke returned from the land of the Waves, the opportunity arose. Izumi had set aside a day off to train, Karin had the afternoon dedicated to her Fuinjutsu training, Kazuma had finished his missions, and Sasuke… Jun had given him the heads up. So Sasuke probably told Kakashi he had something to do. They all met in Jun's living room, three Uchihas, One half Uchiha half Hyuga, one Hyuga, and one Uzumaki.

"Why are we holding a meeting about the Sharingan?" Karin asked." We know Sasuke awakened his; do we need to meet about it?"

"She is not wrong. Jun, you already gave us your speech that we should be careful and all…" Kazuma pointed out hesitantly.

"There must be something else. What is so important for us to meet like this? No one else has awakened his Sharingan since Sasuke no?" Neji added.

Given that the only Uchiha in the room without the Sharingan was Kazuma, it seemed obvious. Because if Kazuma had awakened his Dojutsu, not only would he have told them beforehand, but the meeting would have had a very different tone. 

"You don't know, Neji. It could be Masami." Izumi said with a smile.

"She is three years old! No one is that early." Kazuma replied.

"Haha, you're afraid of getting robbed of your place as a little genius of the family, right?"

"My place of what?! You're talking nonsense. I don't care about that."

Jun observed the scene with amusement. Separately, they seemed all very mature, but as soon as they were together, they turned into kids. Jun also wanted to join in and teased them. But one of them must act like an adult. And since he was the oldest, it was his duty to calm them down. 

"I made a promise to Sasuke to tell him what I know about the Sharingan when he awakened his. But I figured I might as well tell the whole family."

"But we're not Uchihas," Karin said.

"As far as I'm concerned, you and Neji are part of my family," Jun replied.

Karin nodded, a bit embarrassed. And Neji avoided Jun's gaze. He tried to hide his embarrassment as well.

"Let me ask you this, what is the Sharingan?"

"The Dojutsu of the Uchiha." Neji replied, happy to change the subject. 

Jun nodded.

"In theory, all Uchiha can awaken the Sharingan. However, some never do. Others awakened it at a young age and some much later in life. Why is that?" Jun asked.

He let them think about it for a moment before continuing.

"There is a trigger. The Sharingan awakening can be triggered by powerful emotions or tragic experiences. For me, it was seeing my dad die in front of me during the Kyubi assault on the village. For Izumi, it was…" Jun looked at his sister.

"You can say it. I'm fine. For me, it was when Itachi tried to kill me." She said as she subconsciously touched the little scar on her neck where Itachi's sword had grazed her. If Jun hadn't stepped in and blocked the sword, her head would have rolled.

At the mention of Itachi, Sasuke flinched.

"What was it for you Sasuke?" Kazuma asked curiously.

"I'm not sure. That nukenin Zabuza was stepping on me. It wasn't even kicking me. It was stepping on me like I was a vulgar rug. I couldn't stand it. I was so pissed." Sasuke answered.

"For me, it was intense sadness. For Izumi, it was a tragic heartbreak. For Sasuke, it was his strong pride. Anyway… whether it is an intense emotion or a tragic experience when it happens, our brain releases a special chakra that affects our optic nerves, transforming our eyes into the Sharingan."

"Wow," Kazuma exclaimed.

"The lowest stage of the Sharingan is one Tomoe. It allows the user to read the opponent's movement. But it is limited. If the opponent is faster than you, the eye can't keep up. Then comes the two tomoes Sharingan. Not only can you read your opponent's movement, but you can also imitate it. This stage also allows you to anticipate and counter your opponent's moves. A fully mature Sharingan has three tomoes. You can do everything I said before even better and faster. You can cast Genjutsu with a glance. Your speed, endurance, and agility improve." Jun said and activated his Sharingan.

They could see three tomoes in both eyes, a sign of a fully mature Sharingan. He signaled to Izumi who also activated her Dojutsu. She had two tomoes in one eye and three tomoes in the other… Kazuma, Neji, and Karin leaned forward with fascination. Then, they turned to Sasuke. The latter took a deep breath and also revealed his Dojutsu. He had two tomoes in one eye and only one tomoe in the other.

"As you can see, we are all at different stages of the Sharingan."

"How do you get more tomoes?" Sasuke asked.

"Like anything else through training. The more you use it and get better at using it, the faster it matures."

"I studied my Sharingan from the point of view of a medic. Evolution is not excessively difficult. The more the Sharingan is used, the faster it evolves, that's true. But it doesn't evolve in case of chronic exhaustion, which always happens when you overuse your Dojutsu… So don't overdo it, Sasuke!" Izumi warned.

Jun nodded as to support his sister claim.

"However… It is not all. There is another stage to the Sharingan."

"Jun, you…" Izumi's expression suddenly turned serious. "You want to tell them about the Mangekyo Sharingan?"

Jun nodded his head. 

"We shouldn't hide it from them," Jun replied. 

He knew the secrets of Mangekyo Sharingan made Izumi uncomfortable, but they must know about it. Jun believed a part of his sister felt guilty not possessing the Mangekyo Sharingan and not being able to have her eyes as a backup option for him. 

"The Mangekyo Sharingan? What is it?" Sasuke asked impatiently. 

Jun had access to much information from the Uchiha clan archives, which he inherited when he became clan leader, but the Mangekyo was seldom mentioned. What he was about to tell them is from his memories from the Naruto story.

All eyes were on Jun. But the clan leader was staring at Sasuke. They both had their Sharingans activated, and Sasuke could probably see the reluctance on Jun's face. But the clan leader could also read the young Uchiha. His wide eyes in anticipation, the muscles of his neck stiffened in expectation and impatience. 

Sasuke didn't look away. He didn't even blink, staring at Jun with burning intensity. Jun realized how much he wanted to know. The need to know was consuming him. He couldn't let him in that state. So, without taking his eyes off his, he let his Sharingan transform.

The three tomoe grew, extended, and became black bands that crossed and joined, forming a stylized four-pointed cyclone, which slowly swirled around itself. It was his Mangekyo Sharingan.

In the absolute silence that had fallen on the room, Sasuke leaned forward, as if he wanted to burn every single detail to memory. He had a strangely greedy expression. Jun could see Sasuke's desire to possess that power. He sighed internally. He thought he had changed Sasuke. But his desire for power was still there. How far will he go to obtain power? Will he follow Orochimaru again? Jun didn't know. He had done his best to lessen the pain in his heart and will continue to do so.

Izumi suddenly slapped Jun's head. 

"Are you crazy? Deactivate it right away! I can't believe this, did you forget that the Mangekyo can make you blind?!"

Jun's eyes returned to normal. Izumi got in front of him her hands shrouded in medical chakra and she put them over Jun's eyes. Her elder brother grimaced. With his vision blocked, Jun couldn't see the reaction of the kids. But he heard the shocked sounds they made upon hearing Izumi's words.

"What do you mean it makes him blind?"

"You're joking, right?"

"Sensei!"

Jun didn't have the Mangekyo active for a long time, so Izumi's treatment only lasted a few seconds. His little sister took her hands off his face and turned to the four children with a serious air.

"Yes, the Mangekyo Sharingan makes you blind. The Mangekyo's chakra is abrasive by nature. Each use damages the optic nerve. It's like an acid that eats away at it little by little. So the more you use the Mangekyo Sharingan, the closer you get to being blind."

They all looked horrified. Jun grimaced, but there wasn't a good way to announce that.

"Fortunately for me, I have Izumi. She can't undo the damage done in the past, but if she's healing me after every use of the Mangekyo, she can repair recent damage and thus prevent my eyes from getting worse. So my vision is still pretty good. But without Izumi, I would probably be needing glasses to see from afar." Jun said with a smile.

"This is no laughing matter." Izumi intervened. "If he uses the Mangekyo Sharingan, and I'm not around to treat his eyes within a few hours, the damage becomes irreversible."

His attempt at humor fell flat. Especially since Izumi added a layer, throwing a stern look at him. There was silence again. Sasuke had deactivated his Sharingan, suddenly looking almost frightened. Then, he seemed to realize something.

"Then Itachi…"

Jun didn't think he'd make the connection so fast. But indeed, he was right. Itachi had the Mangekyo, and that meant that he suffered the same damage as Jun when he used it… Except that he had no one to treat his eyes. And to make matters worse, Jun knew Itachi solely relied on his Mangekyo Sharingan. He had it on all the time. Jun couldn't understand his reasoning. Why does he walk around with the Mangekyo Sharingan activated?

"Yes, Itachi has the Mangekyo Sharingan. Which means he's slowly going blind. This also means that he will one day seek the solution to his blindness, the Eternal Mangekyo Sharingan." Jun said.

Izumi glared at him, but Jun ignored her. He had said it. Though he knew Itachi's true intentions, he couldn't reveal it. Itachi will indeed seek Sasuke out, but his motive was different form what everyone was thinking about.

"Eternal Mangekyo Sharingan?" Sasuke asked hesitantly.

"The only way known to the Uchihas to solve the blindness issue of the Mangekyo Sharingan is to transplant a close relative's Mangekyo Sharingan. The receiver of the transplant will obtain the Eternal Mangekyo Sharingan… A pair of eyes that will never lose its light. I read in the clan archives that Madara Uchiha took his brother's Mangekyo to cure his blindness. It is the only recorded case I've found." Jun explained.

"And you think Itachi knows this?" Kazuma asked.

Jun nodded. Sasuke became so pale the others worried he might faint on the spot.

Jun felt guilty, but he couldn't tell him Itachi's true intentions. He wouldn't be able to explain how he knew and he wouldn't make sense to them anyway. Also, he wanted to respect Itachi's wishes. He didn't want the two brothers to kill each other though. He would do what he could to prevent that. The truth was Itachi would never harm Sasuke. Yes, he would seek him out but not to take his eyes. Jun knew this. He was probably the only person in the world besides Itachi himself who knew this. Jun wasn't sure how close Itachi had gotten to Obito though.

Sasuke looked down. His fists clenched on his knees. He was shaking a little. 

"But Jun, you're the only one who currently has the Mangekyo Sharingan. Why would he come for Sasuke? Wouldn't it make more sense if he comes after you?" Neji asked.

"It would. The thing is we don't know how related I am to Sasuke's family. The transplant has a high chance of failure. But with a sibling, with such a close relative, the chances are…" Jun didn't finish his sentence.

"So that's why he left me alive. All this time I've been wondering... I was thinking… But that's the real reason he let me leave… for my eyes." Sasuke whispered weakly. 

"But it doesn't matter as long as Sasuke doesn't get the Mangekyo, no?" Kazuma said.

Jun remained silent. He knew things weren't so easy. Itachi will push Sasuke to his limit. He will do whatever it takes to make him awaken it. Jun knew but couldn't say anything. 

Sasuke stood up abruptly. His face was twisted by rage and sorrow. He was on the brink of breaking into tears. His Sharingan was activated as if reacting to his intense emotions. It was normal. He just awakened the Dojutsu. He didn't have complete control of it yet. Jun tried to hold him, but Sasuke avoided his hand and disappeared through the window. 

"Did he just use the Sharingan to dodge, Jun-sensei?" Karin asked.

"Karin, this is not the time. If Jun really wanted to stop him, sharingan or not, he wouldn't be able to go anywhere." Neji said.

"Sasuke!" Kazuma shouted.

He wanted to go after him, but Izumi held him back by placing a hand on his shoulder. Her eyes were full of compassion.

"Give him time to calm down, Kazuma. He needs to be alone right now… I think."

Jun expanded his sensory ninja abilities to keep track of Sasuke's chakra. He also felt two other chakras discreetly following the young Uchiha. Jun was familiar with them. It was two of his cats. Nothing was going to happen to Sasuke. They were inside the village. 

He forced himself to relax. He would give him some time alone and would go see Sasuke later. The boy needed to process everything he just learned.

"Are you sure Itachi will target Sasuke? Karin asked. 

"It's my guess. But I won't let anything bad happen to Sasuke. If Itachi comes, I will stop him again. His eyes cannot beat mine." Jun replied.

Well, he hoped the result would be the same as last time. His Shikigami had destroyed Itachi's Tsukuyomi in their last confrontation. But what about Amaterasu? Would his eyes be able to find the weakness of Amaterasu? He had no idea. Itachi had two Mangekyo powers. Jun only knew of his Shikigami. Was there another power hidden in his eyes or was it only Shikigami? A part of him wanted to train his Mangekyo more in case it held another power. He wanted to unlock it as soon as possible. 

But Izumi would kill him. She took the blindness very seriously. Jun sighed. He needed to get stronger. From what he remembered, Itachi came to Konoha after the Chunin exam, using the excuse of looking for Kyubi's Jinchuriki. However, his true intent was to check on his little brother. It didn't leave Jun with a lot of time.

Sasuke calmed down and returned home a few hours later. No one spoke of targets being ripped apart in the nearby training ground, and the surrounding area being burned by Katon Jutsus. Time ran its course, and little by little Sasuke relaxed again.