After completing the eye transplant surgery, Uchiha Shinji carefully observed the transplanted pair of Mangekyō Sharingan. The eyes now gleamed with vitality, completely different from their prior state.
"Not only has the vision been restored, but it seems even the dojutsu power has been fully replenished."
He marveled at this discovery in his mind and carefully placed the pair of Mangekyō into a specially designed nutrient tank. The liquid inside the tank was formulated based on the latest research from the medical division.
Though the liquid was extremely expensive, it could maintain the organ's vitality for long-term preservation, provided the liquid was regularly replaced.
After securing the recovered Mangekyō, Shinji turned his attention to Karin and her eyes. He asked, "How do you feel?"
Karin blinked a few times, still feeling slightly uncomfortable. "It's still a bit unfamiliar."
"It'll get better soon," Shinji reassured her before pausing and adding, "This pair of Mangekyō has a blind left eye, so this time, you'll need to focus more on taking care of the left eye."
"Understood!" Karin nodded firmly.
Shinji observed her for a moment, then added another instruction: "Don't try to activate the Sharingan, and avoid combat for the time being. Let's wait until the Mangekyō fully recovers."
Realizing how much Shinji valued these eyes, Karin solemnly promised, "Rest assured, I'll take good care of these Mangekyō Sharingan!"
"I'll return tomorrow night," Shinji said, leaving Karin's apartment.
In the following days, Shinji spent his mornings in the medical division's lab, researching Kimimaro's cellular structure or treating patients at the Hidden Leaf Hospital. During the evenings, he immersed himself in medical ninjutsu books, and at night, he visited Karin to check on the progress of the Mangekyō's restoration.
For him, these days were busy but fulfilling.
Seeing how focused Shinji was on medical ninjutsu, his instructor, Kusadō Kaoru, became concerned. During a break, she approached him and offered some comforting words: "I looked up the records, and in your Uchiha clan, only about one or two out of every ten people can awaken the Sharingan. It's rare."
Not understanding why she brought this up, Shinji glanced at her. "And?"
"So even if you don't awaken the Sharingan, it's perfectly normal. You're still young," she hesitated briefly before continuing, "You still have plenty of time to awaken it."
Shinji couldn't help but laugh. "What are you implying?"
Kusadō Kaoru patted his head. "Oh, come on, don't act tough with me! You're an Uchiha. Don't tell me you don't care about the Sharingan?"
"I—"
Kusadō Kaoru interrupted him, "We've all seen your talent. I'm sure you'll awaken your Sharingan, just like Uchiha Sasuke! So stop hiding in the lab and hospital all the time. You're excellent; there's nothing to run from."
"Thank you for the encouragement."
Shinji smiled, realizing that, from an outsider's perspective, his behavior seemed unusual.
Given his natural talent, it was only logical for an Uchiha like him to be entirely focused on training to awaken the Sharingan. Hiding away in the medical lab wasn't something people would expect from him.
Fortunately, there was another plausible explanation: people might assume that, since he hadn't awakened the Sharingan yet, he was feeling discouraged and was using medical ninjutsu as an outlet to cope with his frustration.
"I'll have to be more careful from now on."
After a quick self-reminder, Shinji returned to his lab.
As he examined the samples in his petri dishes, he frowned slightly.
After several days of testing, Shinji had discovered that Kimimaro's cells, while not as domineering as the First Hokage's cells, exhibited strong resistance to fusion.
He had attempted to fuse Kimimaro's cells with his own, Karin's, and even White Zetsu's cells, but every attempt resulted in failure.
Kimimaro's cells seemed almost toxic, completely rejecting fusion with any other cells.
As he tapped his fingers on the desk, Shinji thought to himself, "I wonder if the cells from the Hyūga clan would be able to merge with Kimimaro's."
Without any Hyūga cells to work with, he hadn't conducted such an experiment yet.
Given that none of the cells he had tried could fuse with Kimimaro's, Shinji recalled his original idea of combining the Hyūga clan's Sage Eyes with the Kaguya clan's Sage Body.
"I'll have to find a way to get some of Neji's cells," he mused. "And if possible, I should get Hinata's as well."
He remembered that in the original story, Ōtsutsuki Toneri had said that both Hinata and Hanabi possessed pure Byakugan.
Toneri had chosen Hanabi's eyes to fuse the Tenseigan, while he sought Hinata as his bride to continue his lineage.
Though Shinji didn't know what criteria Toneri used to determine that Hinata and Hanabi had purer Byakugan than the rest of the Hyūga clan, he had clearly been right. After all, Toneri had successfully fused the Tenseigan using Hanabi's eyes.
Since Hanabi was still young, Shinji couldn't approach her. For now, he'd have to set his sights on Hinata.
Two more days passed, making it a full seven days since the previous eye transplant.
Late at night, Shinji once again infiltrated Karin's apartment.
As soon as she let him inside, Karin beamed with joy. "Leader, my left eye—today it can finally see!"
Shinji froze, then a wave of joy washed over him. After a moment, he asked, "Yesterday, you could only faintly see light and shadows. How is it possible you're already seeing clearly?"
Karin shook her head. "I don't know. It just suddenly became clear this afternoon."
"Excellent!"
Inside his sleeve, Shinji clenched his fist tightly.
His efforts over the past days had finally paid off!
Karin, too, was thrilled.
She could tell that her leader cared deeply about these Mangekyō Sharingan, and now that she had helped him, she no longer felt useless.
Suppressing his excitement, Shinji examined Karin's eyes, confirming that the left eye had indeed regained its vitality, transforming from a dull, lifeless white to a healthy, gleaming black.
However, Shinji decided not to activate the eyes yet.
Firstly, his own Mangekyō Sharingan's dojutsu power had been significantly depleted, and he needed to conserve his strength. Secondly, if he activated the eyes now, Karin would discover the two unique dojutsu embedded in these Mangekyō Sharingan.
After careful consideration, Shinji told her, "Tomorrow night, we'll proceed with the next operation!"