It was nighttime.
Itachi had returned home, and after dinner, he was called into the room by Uchiha Fugaku to hear about Kiyosuke's request.
After a moment of silence, he said:
"I understand. I'll go. And I'll be careful."
Uchiha Fugaku opened his mouth, but didn't say anything more—only:
"Tomorrow, go see Kiyosuke-sama."
"Yes."
There wasn't much more to say between father and son. After receiving his father's instructions, Itachi left the room.
...
The next day, he arrived at Kiyosuke's home.
"Your father should've told you everything by now, right?"
Kiyosuke poured Itachi a cup of tea and set it down in front of him.
"Thank you."
Taking the tea, Itachi said:
"I already understand. I'm willing to take on this mission."
"Good. Then the only people you need to watch out for are my teacher, Orochimaru, and that masked man."
Kiyosuke said:
"The masked man is from the Uchiha clan. His real name is Uchiha Obito."
"Uchiha Obito?! Isn't that Captain Kakashi's—"
"That's right. Kakashi's former teammate. His Sharingan also came from Obito."
Kiyosuke continued:
"One of Shisui's Mangekyō Sharingan eyes was stolen—you know that, right?"
"Yes."
"That eye was used to control Obito."
He didn't mention that he still had that eye. It had other uses for him.
"So that means... he's being controlled too?"
"Yes. He awakened his own Mangekyō Sharingan, also due to Shisui's eye. His Mangekyō ability is a space-time ninjutsu—it allows him to transfer his body from one place to another. If you attack him, the part being attacked will automatically shift into that space-time dimension. Only in the instant of transfer, and the moment the attack ends, does his body return to physical form."
Kiyosuke briefed Itachi on everything about Obito, warning him to stay alert.
"Also, keep an eye out for someone called Zetsu. He's half black, half white. If you can, try to keep tabs on him—or better yet, capture him. He's the root of all evil. Just the black half is enough. Be very careful of that part. It can possess and control people. Understood?"
Itachi took the warning seriously.
"I understand."
"And my teacher... well, he's hungry for your body."
"…"
Although he'd already heard about this from his father the night before, Itachi still felt something was off about it.
"I mean it in a purely physical sense. Just remember—don't get too close to him. Once you join the Akatsuki, he'll try all kinds of ways to get near you. Not that resisting him will do much—he's probably the hardest person to kill in the entire ninja world. So just handle it as you see fit."
"…"
Are you really his student?
"Alright then. Meet us at the Konoha training field tonight. Shisui and I will give you some special training."
"Yes."
...
That night, at the Konoha training field.
Kiyosuke and Shisui arrived together. Itachi jumped down from a tree and asked:
"Kiyosuke-sama, what kind of special training?"
Kiyosuke blinked and smiled.
"It's simple. This is training to help you awaken the Mangekyō Sharingan."
"Awaken the Mangekyō Sharingan?"
Itachi was surprised.
"But... to awaken it, don't you have to—"
To awaken the Mangekyō Sharingan, one must undergo intense emotional trauma—pain that tears through the soul.
"Exactly. So—sacrifice yourself for the greater good! Shisui!!"
Before Itachi could react, Kiyosuke drew a kunai and stabbed it straight through Shisui's chest.
Blood sprayed across Itachi's face.
"Shisui…"
Itachi raised his hand and wiped at his face. Staring at the blood on his palm, he was completely stunned.
He watched as Kiyosuke pulled his hand out of the gaping wound in Shisui's chest, smiling wickedly.
"Come on. Feel the pain!"
"Aaaaaahhh!!!"
To Itachi, Shisui was his best friend, his mentor in ninjutsu, like an older brother to him. And now... right in front of his eyes...
Shisui looked down blankly at the hole in his chest. He gave Itachi a faint smile, then collapsed backward.
His body didn't hit the ground—it was caught in Itachi's arms. Tears streamed down his face.
"Shisui! Shisui!!"
"Cough cough... Itachi, for Konoha…"
Shisui's head tilted. He drew his last breath.
"No! Shisui! Aaaaaahhh!!!"
Itachi clutched Shisui's lifeless body and let out a grief-stricken wail.
His dearest friend—his brother in all but blood—had died before his eyes in such a dramatic, tragic way. How could he accept that?
How could he accept it?!!
"Aaaaahhh!!"
His eyes began to burn, as if set ablaze.
His visual power surged exponentially. The tomoe in his eyes spun so fast they became a blur—until they fused together into a windmill-like triangle: the Mangekyō Sharingan.
Seeing this, Kiyosuke nodded and said:
"Alright, Kiyosuke-sama, that's enough lying around. Get up."
"Huh?"
Still consumed by grief, Itachi couldn't comprehend what was happening. The "Shisui" in his arms suddenly turned into Kiyosuke and sat up.
"Can't believe awakening your Mangekyō was this easy. I was prepared to have Shisui fake his death anyway."
The "Kiyosuke" off to the side turned into Shisui, who said:
"Itachi, you're still too young."
"This was your plan all along?"
"Of course. To awaken the Mangekyō Sharingan, you need to experience intense sorrow—that's what triggers the evolution of your eyes. Since you're going undercover in the Akatsuki, I was a little worried. We needed to boost your power."
They had swapped identities, and Shisui had used his Mangekyō Sharingan to cast a genjutsu—tricking Itachi, who didn't have the Mangekyō yet.
"Here, wipe that off."
Shisui handed him a tissue so he could clean the blood at the corners of his eyes.
"I didn't agree with Kiyosuke-sama's plan at first—having you awaken the Mangekyō. But after learning how dangerous your mission is... Itachi, you need it. Just don't rely on it too much. If you do, your eyes will be consumed by darkness."
"I understand. You guys..."
Itachi sighed helplessly. He wasn't used to the Mangekyō's strain on his body just yet, but he was relieved—Shisui was alright. That was all that mattered.
Kiyosuke said:
"Next… Shisui, go ahead and fake your death."
"Huh?"
"I need to give Uchiha Itachi a reason to 'betray' Konoha. You faking your death is the perfect excuse."
If Itachi wanted to join the Akatsuki, he had to become a rogue ninja.
But right now, he had no reason to betray Konoha.
So, Kiyosuke decided to give him one.
Shisui's 'death' would be the cause that pushed Itachi to 'defect.'
"I get it."
Shisui accepted the mission and said helplessly:
"You really are something. Why's your talent gotta drag me into this too?"
"It's not like I wanted to."
Itachi shook his head.
"But this way, at least I know what I'm doing."
"Alright then. I'll work out the final details. Itachi, don't take any missions for a while. Spend some time with your family."
"Got it."