The next day, Sakura began her formal training.
Tsunade took her to a fresh market outside Tanzaku Quarter and bought several live fish.
"In your view, what is Medical Ninjutsu like?"
Having heard from Jiraiya about Sakura's genius, Tsunade started with a test.
"I don't know!"
Sakura answered bluntly. Although she had read the notes Tsunade gave her, she felt this Ninjutsu was more like a science, encompassing techniques, pharmacology, pathology, clinical studies... and other disciplines.
So, as a novice, not casually defining an unfamiliar field was Sakura's most basic humility as a learner.
After hearing this, Tsunade pondered for a moment and said, "In others' eyes, we Medical-Nin can't fight, our techniques are extremely difficult and complex, our knowledge is vast and cumbersome, and learning is full of stumbling blocks. That's all because they haven't grasped the essence of Medical Ninjutsu!"
Tsunade raised a finger and gently tapped Sakura's forehead. Green Chakra glowed, and a warm current flowed through her finger into Sakura's body.
"The essence of Medical Ninjutsu is very simple. Put plainly, it's the Ninja's use of their own Yang Attribute Chakra. All the various techniques beyond that are merely applications of Yang Attribute Chakra's Nature Transformation!"
Tsunade had explained it to this extent, and Sakura roughly understood her meaning.
"The essence of Ninjutsu?"
Hearing Sakura's murmur, Tsunade's eyes lit up, "Exactly!"
"Chakra is a product of the balanced mixture of two energies. During extraction, the body's physical energy is inevitably mobilized. Separating this force from the chakra to stimulate the patient's cells… that is the most basic Medical Ninjutsu!"
"So the essence of Medical Ninjutsu lies in the Ninja's control over their own chakra. The finer the control, the more physical energy can be separated, and the better the effect of the Medical Ninjutsu!"
"But you must also note that stimulating cells, to some extent, consumes the patient's life force. Therefore, Medical Ninjutsu practice must focus on subtle control."
After explaining the essence of Medical Ninjutsu, Tsunade stood up and pulled a small jar from her cleavage.
She poured the liquid inside into a bucket of live fish. The paralyzing poison entered the fish's bodies, and the entire bucket of fish floated belly-up on the water.
"Today, I'll first teach you the lowest difficulty among all Medical Ninjutsu… the B-Rank Jutsu, the Delicate Illness Extraction Technique."
As she spoke, Tsunade pulled a fish from the bucket, formed hand seals, and directly gathered the poisons from the fish's body into her hand, forming a small droplet.
"Your practice task today is to extract the entire bottle of poison I just used, and you must not let the fish die."
"Well, can you keep up? If not, I'll have to send you back!"
"Don't worry! There's no Ninjutsu in this world I can't learn!"
Sakura had already used her Observation Haki to sense every flow of Tsunade's Chakra. She imitated the process, trying to separate the physical energy from her Chakra, then a hint of green appeared in her palm.
She stepped forward, took the fish from Tsunade's hand, and began practicing.
Watching the girl training hard, Tsunade jumped onto a nearby roof.
Shizune, her long-time disciple, arrived and handed her a flask of sake.
"Tsunade-sama, you're being too mean."
Shizune held Tonton in her arms, looking pityingly at the girl below.
"Although the Delicate Illness Extraction Technique has low training difficulty, its requirement for perception is no less than other A-Rank Medical Ninjutsu!"
"Heh heh, I'm making this child back down from the difficulty."
Tsunade sipped her sake, munching on dried fish snacks.
"That Jiraiya just dumped his disciple on me without a word, and he even put on that act in front of me. I couldn't refuse outright."
"Now, by giving her a technique with a hidden threshold, letting the child hit a soft wall… a genius like her will weigh the options and quickly back down from the challenge."
"Something as exhausting and effort-consuming as taking on a disciple? I can't be bothered."
In high spirits, Tsunade downed the entire flask of sake in one go, secretly praising her own cleverness.
"Huh? Success!"
Sakura placed the detoxified fish back into the bucket. The entire bottle of poison Tsunade had just poured into the fish's stomach had been completely separated.
Sakura raised the now wriggling live fish in her hand and waved at the stunned Tsunade on the roof.
"Tsunade-neesan, look, I succeeded!"
"Shizune!"
Tsunade's gaze sharpened. The pink-haired little girl in front of her was becoming more and more pleasing to the eye.
'She spoke sweetly, was adorable, had superb gambling skills, and possessed unparalleled talent in Medical Ninjutsu.'
'Damn it, how did such a good child get snatched up by that pervert Jiraiya?!'
'But thankfully, the child is willing to learn Medical Ninjutsu. This is my chance!'
"What is it, Tsunade-sama?"
The confused Shizune bent down, bringing her ear closer to Tsunade.
"Would you mind having a junior sister?"
Tsunade chewed vigorously on the salted dried fish in her mouth, making a crunching sound.
"Huh? But you just said you didn't want to take on any more disciples!"
"But then again..."
At this moment, Tsunade's mind was already fantasizing about taking this little girl away.
In the future, the master and disciple would conquer the casinos together… Sakura would be responsible for winning, and she would be responsible for enjoying!
Wiping the drool from the corner of her mouth, Tsunade took a step forward and dropped down from the roof.
"Your name is... Sakura, right?" Tsunade cleared her throat, using her fist to cover her mouth, "Do you want to learn even more powerful Medical Ninjutsu?"
"Even more powerful?"
Sakura could guess what Tsunade was up to, but she still widened her innocent emerald-green eyes.
"That's right! Medical Ninjutsu that can heal hundreds of people at once!"
Taking a deep breath, Tsunade's face couldn't help but show a hint of pride.
During the Great Ninja War, she alone healed hundreds of poisoned Ninja, single-handedly thwarting Sunagakure's attack on Konoha.
"I'll learn it!"
Since Tsunade was willing to teach, Sakura naturally wouldn't refuse.
With Sakura's agreement, Tsunade didn't hesitate. She clasped her hands together and bit her finger.
"Summoning Technique!"
After her palm slapped the ground, she looked at the smear of bright red and trembled.
Her whole body went weak, and she fell backward, but the thing that appeared in the smoke timely caught her, preventing her from hitting the ground.
"Tsunade-sama?"
"Long time no see, Katsuyu."
Tsunade weakly raised her hand and placed it on Katsuyu. The other party's Chakra immediately flowed into Tsunade's finger, instantly healing her wound and cleaning the bloodstain.
"What do you need me for?"
"I found a promising child. Could you see if she can sign the Shikkotsu Forest's Summoning Contract?"
Tsunade, who had recovered a little, waved Sakura over to let Katsuyu have a look.
"Ara, another child with great spirit~"
Katsuyu wriggled and crawled onto Sakura. Its cool, soft body lightly touched her skin.
"Hmm, you also have a very pleasant scent on you. It's the smell of Space-Time, isn't it~"
Facing this ancient Sage's split body of unknown age, Sakura felt inexplicably nervous.
She always felt those mottled eyes could see through all her secrets.
Just as Sakura was feeling extremely uncomfortable under the scrutiny, Katsuyu suddenly spoke: "You're a good child. I quite like you~ Let's make a contract!"
As she spoke, Katsuyu opened her mouth and spat out a scroll from her abdomen.
"Write your name on it and drip your blood onto it."
Katsuyu instructed Sakura in a gentle voice on how to form a Summoning Contract with her.
Only after Sakura dripped her blood onto the scroll did Katsuyu's steady voice carry a hint of joy.
"Then, from now on, we are partners fighting side by side, Sakura-sama!"
"Of course, I'm very happy to be your partner, Great Katsuyu Sage!"
"Ara ara~ a clever child."