Under the waterfall, Kimimaro sat shirtless on a stone.
The powerful stream of water constantly pounded against his body, but he remained motionless, his skin emitting a blue glow.
This blue glow was unique to the Palm Healing Technique.
Originally, the blue light only appeared in his hands, but now it flowed throughout his entire body.
With the help of this blue glow, the force of the waterfall couldn't harm Kimimaro's body. Instead, it was quickly converted into a means of tempering his body, making it stronger and sturdier.
The blue light gradually dimmed, as if it could no longer be sustained.
At that moment, Kimimaro opened his eyes. His right hand extended, and from the palm, a bone sword shot out, which he grasped firmly.
"Devil Sword Slash!"
Kimimaro lightly tapped his toes, and his whole body leaped into the air!
Where the bone sword pointed, a dazzling flash of light erupted, instantly splitting the waterfall in two.
In the blink of an eye, Kimimaro, carving a path with his sword, passed through the waterfall and landed gracefully on a large rock above it.
Pikachu was training nearby.
Its lightning-shaped tail had turned into a steel color and was repeatedly striking a large rock.
*Clang! Clang! Clang!*
The tail's impact produced sounds like steel striking metal.
After hundreds of hits, the large rock cracked and then shattered!
"Hey, little guy, come help me with my training."
Hearing Kimimaro's words, Pikachu immediately stopped training its tail, steadied itself, and sparks of golden lightning flashed from the two red circles on its cheeks.
"Pika... Pikachu!"
*Thunderbolt!*
Pikachu's signature move.
Golden lightning erupted from its body, striking Kimimaro.
The power of the lightning was already comparable to a mid-level ninja's Lightning Style technique.
But Kimimaro bathed in the thunder with a look of enjoyment, completely immune to any harm.
The lightning strike lasted for about a minute before Pikachu stopped, looking exhausted.
"You worked hard, little one."
Kimimaro gently patted Pikachu's head and put on the clothes beside him.
"Pika!"
Pikachu jumped up and landed on Kimimaro's shoulder.
"It's been two years, and my physical strength has improved tremendously compared to before. Tsunade-senpai's methods really work. But I couldn't have come this far without the help of this little guy."
Unknowingly, Kimimaro had already lived in the Land of Tools with Tsunade and Shizune for two years.
During this time, most of his focus had been on improving his physical strength.
Training under waterfalls and lightning tempering were common yet effective methods.
At first, training under the waterfall caused Kimimaro to be swept away by the water before he could even steady himself.
His body was often left bruised and battered.
Fortunately, with the help of medicinal herbs, these injuries not only didn't harm him but also strengthened his body.
Six months ago, Kimimaro was finally able to move freely under the waterfall.
From then on, he started practicing sword techniques under the waterfall, training his strength, which led to the scene just now.
As for lightning tempering, it was inspired by the secret technique of the Hidden Cloud Village—Lightning Release Chakra Mode.
With Pikachu, the Thunder-type beast, around, using this method became extremely convenient.
At the same time, it helped Pikachu train its control over the intensity of its electricity.
Kimimaro had progressed from not being able to withstand even basic electric shocks to now enjoying the effects of Pikachu's *Thunderbolt* attack, showing remarkable improvement.
Every muscle on his body was now a product of two years of intense training.
Of course, this was only part of his training during these two years.
The most important issue was his Kekkai Genkai disease.
Though Tsunade's research had made some breakthroughs, the results were not promising.
They had yet to begin any actual treatments.
Instead, they spent time exchanging medical knowledge and studying the disease together, hoping to spark new ideas.
During this period, Kimimaro taught Tsunade the *Stitching with Chakra Threads* technique.
Initially, he thought Tsunade wouldn't be able to learn it due to the differences in training systems.
However, since the version of the technique he used was powered by chakra, Tsunade was naturally able to learn it.
After learning the *Stitching with Chakra Threads* technique, Tsunade realized how brilliant it was.
Her admiration for Kimimaro grew.
To think that this young man could develop such an advanced medical technique on his own was truly terrifying.
Tsunade even thought that, given a few more years, her title as the greatest medical ninja in the ninja world might have to be passed to him.
To balance things out and to help with his Kekkai Genkai disease, Tsunade decided to teach Kimimaro the Yin Seal.
The Yin Seal, passed down from Uzumaki Mito, was the basis for Tsunade's development of the *Strength of a Hundred Seal*.
It was well known that chakra was a combination of physical and spiritual energy, and it only gathered when performing a technique.
When not in use, chakra wasn't retained in the body.
This was why most ninjas had high attack but low defense.
Without actively channeling chakra, a ninja's body was no stronger than a regular human's and couldn't resist sharp weapons.
Only ninjas who had trained their muscle density to a high level could have adequate defense without constantly using chakra.
The Yin Seal broke this rule of chakra not being stored in the body.
It allowed a person to create a storage space within their body to hold excess chakra gathered over time.
For those with limited chakra, this was a godsend.
However, there was one important thing to note.
The chakra stored in the Yin Seal had to remain untouched for three years.
During these three years, the chakra in the Yin Seal could not be used, even for an instant, or the entire process would be undone.
Moreover, the amount of chakra required for the Yin Seal was at least two-thirds of the user's total chakra.
In other words, for three years, only one-third of the user's chakra would be available for training and battle.
After three years, once the Yin Seal was complete and a diamond-shaped mark appeared on the forehead, the process was considered successful.
The biggest challenge, however, was the precise chakra control required throughout the process.
This level of control could only be achieved by top-tier medical ninjas.
Regular ninjas had no chance.
Even a medical ninja of Shizune's caliber couldn't manage it.
Once the Yin Seal was formed, it offered three main benefits:
First, the user could fully access their chakra again, and upon releasing the Yin Seal, they would gain a multiple of their chakra.
Even if the stored chakra was exhausted and the diamond mark disappeared, it would not require another long process to rebuild. The mark would reappear as long as the body recovered.
Second, the Yin Seal could finely adjust chakra, boosting the body's functions and effectively halting the aging process, which was the reason Tsunade wanted to teach it to Kimimaro.
By making these adjustments, Kimimaro would have a clearer understanding of his body's condition and could formulate treatment plans accordingly.
Third, it allowed the use of the forbidden techniques *Creation Rebirth* and *Strength of a Hundred Technique*.
*Creation Rebirth* instantly heals all wounds but at the cost of lifespan.
The *Strength of a Hundred Technique* floods the body with chakra, enhancing overall abilities.
Tsunade hadn't taught Kimimaro these forbidden techniques yet, as there was no need.
These three benefits showed just how powerful the Yin Seal was, and learning it was classified as S-rank difficulty.
Kimimaro had only been practicing for a year and would need two more years to fully form the diamond mark.
Having only one-third of his chakra available was a challenge, but he had grown rapidly over these two years, and his chakra levels were surging.
Even with only a third of his chakra now, it was more than what he had two years ago.
What interested Kimimaro the most was the principle behind the Yin Seal.
If this principle could be applied to the Cursed Seal, not only would it solve Jūgo's problem, but it could also help Kimimaro create a perfect Cursed Seal for himself.
However, he needed to wait until he fully formed the Yin Seal before considering this further.
At present, his abilities are not enough to accomplish this.
Laboratory.
Tsunade stared at the white bones before her, her expression grave.
The white bones were gradually turning gray, looking quite eerie.
"It must succeed!"
For two years, she tried many methods, hoping to make the energy within the bones milder.
But hundreds of experiments failed.
The only consolation was that there was a little progress each time.
And this was the three hundredth experiment.
Under Tsunade's gaze, the white bones stopped just as they were about to turn completely gray.
At the end of the bone, the last bit of white remained!
"Success!"
Tsunade was overjoyed!
"Tsunade-senpai, what's making you so happy?"
Kimimaro had just returned from training and asked when he saw Tsunade's joyful expression.
"Kimimaro, come and see. After a series of operations, the white bone stopped when it was about to completely turn into gray bone. This means that its energy has become much milder.
Although it's just experimental data, there's a fifty percent chance that it can completely suppress your bloodline disease."
Kimimaro showed a hint of a smile. Although there was good progress, this was not the result he wanted most.
Suppressing the power within his body was like blocking a flow, and it was better to疏导than to block.
He wanted to completely solve this hidden danger, not just suppress it.
Because no matter how much he suppressed it, his bloodline disease would not disappear.
But, having a way was better than having no way at all.
"Cough, cough, cough..."
Kimimaro suddenly started coughing violently again.
Tsunade's face showed concern, and she stepped forward and gently patted his back.
"Are you okay?"
"I'm fine, it's just an old problem. Tsunade-senpai, I'm willing to try this method. Even if it only extends my life for a few years, it's better than dying. After all, there's hope in living."
"Kimimaro, don't worry. After this treatment, I should be able to find a cure."
(End of Chapter)