"Shizune, stay here and help me approve these documents. I'm going to treat Kakashi!"
Shizune had just returned with the medical records, barely catching her breath, when she heard Tsunade's instructions.
Approve documents?
Looking at the towering stack of paperwork, Shizune's expression changed instantly.
"Tsunade-sama, this is the Hokage's authority. I'm just an ordinary jōnin—I don't have the qualifications!" As a normal shinobi, Shizune still held deep respect for the Hokage.
In her eyes, these documents were something only the Hokage should review. For her, a mere jōnin, to even look at them felt like overstepping boundaries.
"Just do as you're told! Why so much nonsense?"
"I'm going to save someone. Hikari, come with me. Shizune, just approve them. If there's anything important or something you're unsure about, set it aside."
With that, Tsunade grabbed the medical records from Shizune's hands, called out to Kamizuki Hikari, and strode out the door.
Hikari glanced at the stunned Shizune, and sent her a sympathetic look before quietly slipping away behind Tsunade.
---
Konoha Hospital, Kakashi's ward.
Tsunade was examining Kakashi, her heart filled with shock.
She knew the effects of the nutrient solution she had formulated.
It definitely had healing properties, but nothing this powerful.
Right now, Kakashi's chakra reserves had more than doubled, and the rejection of his left eye by his body had decreased to its lowest level.
If she hadn't heard Hikari's inner thoughts, she might have assumed that this was the result of Kakashi's body naturally adapting to the Sharingan after years of use, eventually achieving genetic compatibility.
But now, that explanation wouldn't hold up.
She was truly curious—how exactly had Kamizuki Hikari solved the issue of the Sharingan's rejection?
'Forget it. There's still time. Today, I'll focus on healing Kakashi. The rest can wait.'
With that decision made, Tsunade's hands glowed with green chakra as she pressed them onto Kakashi's head.
[Boom!]
[At this moment, within Kakashi's mind, it was as if the heavens and earth were splitting apart, a singularity exploding to create a new world.]
[Kakashi felt a massive shift in his spirit. Beyond that, his left eye... within it, he sensed a mysterious power...]
Tsunade couldn't help but close her eyes.
Kamizuki Hikari, that bastard, was narrating in his head again.
Hearing this, she almost mistook it for Kakashi's actual thoughts.
"Huh? You are... Tsunade-sama!?"
Due to his prolonged unconsciousness, Kakashi felt disconnected from his body upon waking. His vision was blurry, making it difficult to see clearly.
Fortunately, his Sharingan quickly adjusted, allowing him to recognize the person before him.
"How do you feel?" Tsunade asked with concern.
Kakashi closed his eyes and silently assessed his body.
His chakra reserves had doubled, his mental state was excellent, and most notably, his left eye... It felt just like an ordinary eye, no longer burdened as before.
With a slight surge of chakra, Kakashi noticed a drastic improvement in his vision.
He could see clearer. Further.
'Tsunade-sama's chakra is overwhelming... As expected of the Senju Clan.'
'And Hikari... It's as if a layer of white mist surrounds him, making it hard to see... Wait, the mist disappeared. His chakra is only at the level of a chūnin? Was I imagining things just now?'
"Kakashi, don't use chakra to stimulate your left eye yet. Take a look in the mirror and tell me if you notice anything different!" Tsunade instructed while handing him a mirror.
Staring at the transformed shape of his three-tomoe Sharingan, Kakashi was stunned.
"This is..."
"The Mangekyō Sharingan." Tsunade explained.
Kakashi understood immediately. "This is the same level of eyes as Uchiha Itachi's... But wasn't mine just a three-tomoe? How did it evolve into a Mangekyō?"
Tsunade remained silent.
Could she just admit that she had no clue?
[Obviously, it's because when Tobi witnessed Rin's death, his hatred for the world triggered the awakening of his Mangekyō Sharingan. Since Kakashi possessed Tobi's other eye, his Sharingan evolved along with it.]
[This is the rare eye that grants the space-time ninjutsu Kamui—it must be kept hidden. If Tobi ever realizes, he might come to steal Kakashi's eye, and that would be a disaster.]
[After all, I don't want to stand out. Being a lazy bum is just fine.]
So, Tobi... is Obito?
As one of Konoha's renowned geniuses and a former student of the Yellow Flash, Namikaze Minato, Kakashi was well-known to Tsunade, along with his teammates, Nohara Rin and Uchiha Obito.
She just wasn't very familiar with them.
'Hikari is far too mysterious... How does he know so much?'
Her curiosity only deepened.
"Kakashi, you need to learn to control this eye slowly. Unless absolutely necessary, do not let anyone find out about it. Understood?" Tsunade warned.
Kakashi was an intelligent man. Even if Tsunade hadn't said anything, he wouldn't have carelessly exposed this information.
For a shinobi, concealing one's own abilities was paramount.
This was evident in Hidan's case.
With his pseudo-immortality granted by Jashin, anyone unaware of his secret would easily fall victim if he obtained even a drop of their blood. He could then use his curse ritual to kill them instantly.
But the moment his abilities were exposed, even the new-generation Ino-Shika-Chō trio could take him down.
As an elite jōnin of Konoha—and part-time Konoha technician—Kakashi naturally knew how to keep his techniques hidden.
Now, he felt like the Sharingan was merely an external tool. As long as he didn't actively use it, it remained dormant, having no negative effect on his daily life.
Even using three-tomoe-level vision to perform techniques like Chidori and Raikiri wouldn't impose much burden on his body anymore.
At this moment, he felt as if a great weight had been lifted off his shoulders.
He, Hatake Kakashi, was back in action.
"Thank you, Tsunade-sama, for treating me. I will keep this a secret and will not use this eye unless absolutely necessary."
Mistakenly credited as the main person responsible for his treatment, Tsunade awkwardly glanced at Hikari, only to see him lazily leaning against the door, dozing off without a care.
This made her discard the last bit of shame in her heart.
'That's right, the one who healed you was me, Senju Tsunade. Be grateful!'
Of course, she wouldn't say that out loud. She could quietly take credit but couldn't be too blatant about it.
Staying low-key was her style. (Mostly to avoid embarrassment if she got exposed. This way, even if the truth came out, she could always feign ignorance and deny involvement.)
"Good. Just focus on recovering quickly. Konoha needs you."
"Understood. I will recover as soon as possible."
There was no need to think too much about it—Kakashi knew that during a power transition, Konoha would be at its busiest.
No need to ask why. This was all based on experience.
Just think about when Minato died and the Third Hokage took over again.
Think about Danzo attempting an assassination during that time.
Kakashi knew he had to recover quickly.
Konoha still needed him, and he couldn't afford to fall now.