Tsunade's Laboratory

Early the next morning, in order to avoid drawing attention, Uchiha Yū arrived at Konoha Hospital while there were still few people around.

Thanks to Tsunade's vigorous promotion, Konoha Hospital had not only ordinary doctors, but also medical squads in training.

However, it was not wartime, so few people were injured while carrying out missions. In order to recruit more volunteers, the Hokage had specifically arranged for some ninja to undergo regular physical examinations at set intervals.

"Ahhh! Help!"

"You medical squads have gone too far! We're cooperating with you, not letting you use our bodies for experiments!"

"It hurts, it hurts! What's with that syringe? Why are you stabbing it into my kidney?!"

The moment he arrived at the medical squad's section of the hospital, he saw two ninja rushing out in a panic. Their faces were filled with terror, as though they had seen the most horrifying thing in the world.

One of them even had a needle stuck in his kidney area and was desperately running outside. But at that moment, a capable-looking woman suddenly appeared at the entrance.

Dressed in a white lab coat, she caught the two escapees and dragged them back. Using the gentlest tone she could manage, she said:

"The Will of Fire teaches you to make sacrifices. In order to advance medical ninjutsu and help more injured people keep their lives, this small sacrifice is necessary!"

"You should be able to make sacrifices for the village, right?"

Like catching chicks, Tsunade held the two firmly in her hands, lifted them up, pinned them against the wall, and continued:

"If you're unwilling, that's fine too."

Those words gave the two of them hope. They looked up at Tsunade and tentatively asked:

"Really? Then we'll be leaving..."

"You misunderstood what I meant."

Tsunade gave a light squeeze, then slammed a fist into the wall behind them, spreading cracks across a wide area.

"What I mean is, if you aren't volunteers, then I'll help make it a reality. Don't worry, with me personally handling it, it won't affect your careers as ninja."

Amid their struggles, the two were dragged back into the operating room.

And Uchiha Yū, who had just pushed open the door and entered, happened to witness that scene.

At that moment, he was utterly bewildered. He had thought entering Tsunade's laboratory would already be miserable enough, but now he realized he had still underestimated just how ruthless Tsunade was.

If she stuck a syringe into his kidney...

He could not help shuddering.

Run! He had to run! He absolutely could not fall into Tsunade's hands.

Unfortunately, Tsunade spotted You as soon as he entered the experimental area. A figure appeared behind him, blocking his wheelchair, placing both hands on his shoulders, and lowering her head to face him.

From his low position, his view upward was completely blocked by a pair of mountains. Anyone with such an impressive bosom could only be Tsunade, even without seeing her face.

"Good morning, Lady Tsunade!"

"Good morning. I'm sorry you had to see that."

Without waiting for his consent, Tsunade pushed his wheelchair forward. Perhaps feeling that what had just happened was too violent and did not fit her image as a doctor, she forcibly explained:

"But they were all volunteers. In order to promote the development of the village's medical ninjutsu, necessary sacrifices must be made. Besides, medical ninjutsu can stimulate their cells and make them stronger."

"Don't overthink it."

She lightly patted his shoulder. If he had not witnessed that scene just now, he might have believed that Tsunade was merely conducting normal experiments.

Now, even though Uchiha Yū knew he had boarded a pirate ship, there was no way to escape once he was inside Tsunade's experimental area.

"Lady Tsunade! Please go a little easier on me during the upcoming experiment!"

The only response he received was the scenery rapidly retreating around him. Afraid that something else might happen, Tsunade immediately took him to the experimental area.

Once inside, it was nothing like he had imagined. He had expected a bloody experimental table, but instead found a spotless white corridor, with rooms lining both sides and ninja patrolling at fixed intervals.

The security measures here could be called among the best in the village. Even an elite ninja would be unable to force their way in.

Just as Tsunade had said, even when conducting human experiments, she would ensure the ninja's lives and futures.

After passing through the corridor, they arrived at a concealed door. Beyond it was Tsunade's laboratory, the most crucial place in the entire area. Two elite ninja stood guard outside the door alone.

"Lady Tsunade!"

"Lady Tsunade!"

Only after a series of inspections could they enter. Konoha's most precious medical ninjutsu was preserved here.

Looking at Uchiha Yū lying on the operating table, Tsunade guiltily shut the door. Now there was absolutely no way for him to escape. With a trace of apology, she said:

"Ahem, let me make this clear in advance."

"This ninjutsu is still in its developmental stage. Although it has already shown obvious results, it comes with pain. You'll have to endure it."

Before You had a chance to say anything else, a mass of green chakra appeared in Tsunade's hand.

"Advanced medical ninjutsu! Mystical Palm Technique!"

Her chakra control was practically monstrous. Despite having trained so many medical ninja, only a few were capable of mastering the Mystical Palm Technique.

Layer after layer of bandages were unwound. Compared to a few days ago, the skin had improved somewhat. Now, only below his knees remained a mess of flesh and bandages tangled together.

Uchiha Yū could feel a warm stream of chakra moving through his entire body. This chakra stimulated his cells, using stimulation to promote their recovery.

However, because it had not absorbed enough sunlight, the newly regenerated cells were immediately destroyed by the domineering radioactive elements within his body.

Throughout the process, he also had to restrain himself with great care. Radioactive elements were extremely harmful to ninja; even an elite jonin exposed to them would suffer genetic mutations.

In order to let Tsunade perform the operation smoothly, he had gone to great lengths.

However, one thing was certain: the Mystical Palm Technique was somewhat helpful to his body, because it contained Yang-nature chakra. Unfortunately, it still differed somewhat from the Yang nature found in nature itself.

That was why the healing was so slow.

"What a strange condition."

Tsunade lowered her head to look at the sloughed-off flesh. All of it had been contaminated by radioactive elements. It blackened at a visible rate before finally turning into a puddle of rotten sludge.

She placed it beneath a special instrument. With its assistance, the flesh was magnified, revealing the completely destroyed cells within, and her brows furrowed tightly.

"It can be confirmed that there is some strange element in your body, but further research is needed before I can determine what it is."

The radioactivity in the flesh destroyed by You's uranium element had already been reabsorbed by him, so Tsunade could not detect it.

Unfortunately, Tsunade's research focused on the human body. If it had been Orochimaru instead, he really might have been able to figure it out.