Tsunade was still young at this point in history, only in her early thirties.
Through extraordinary chakra control and a transformation technique sustained by the reserves stored in her Yin Seal, she appeared even younger. Her skin showed no trace of age, and the combination of mature confidence, fierce authority, and heroic spirit made her unforgettable.
Ren could not help observing her for a few extra seconds.
This was Tsunade Senju—the granddaughter of the First Hokage, a student of the Third Hokage, one of the Legendary Sannin, and the shinobi who had revolutionized Konoha's medical system.
More importantly, she possessed several techniques Ren wanted to learn.
Tsunade noticed his stare immediately.
Her golden-brown eyes narrowed as they moved from Rin to Ren. "Are you finished inspecting me, brat?"
Ren calmly lowered his gaze. "I was only surprised to meet one of the Legendary Sannin in person."
"Hmph. At least you know how to answer."
Tsunade lifted Hebiji's recommendation letter and scanned the final section again.
"So, you're the two children Hebiji recommended." She pointed toward two patients resting beside the window. "Treat them. Shizune will watch your work and stop you if either of you does something stupid."
"Yes, Lady Tsunade," Shizune replied.
Rin straightened nervously. "We understand."
This kind of examination was expected. Tsunade would never admit two young genin into an advanced medical program based solely on someone else's praise.
The patients beside the window had already been stabilized, so neither was in immediate danger. However, their injuries were complicated enough to test medical judgment, chakra control, and practical technique.
The first patient had several deep lacerations along his shoulder and upper arm. The second had suffered a violent impact to his thigh, leaving the flesh torn and the surrounding muscles badly damaged.
Ren and Rin exchanged a glance before moving toward separate beds.
Rin began with the patient suffering from lacerations. She checked his pulse, breathing, and pupil response before carefully removing the temporary bandages.
Ren examined the thigh injury.
The outer wound had been cleaned, but fragments of dirt and cloth remained embedded in the deeper tissue. Several blood vessels had ruptured, and part of the muscle had curled inward around the wound.
He would need to clean it again before using medical ninjutsu. Attempting to force the flesh closed immediately could trap contamination inside and cause infection.
Shizune moved between the two beds.
She first observed Rin.
Although Rin's hands were slightly tense, her procedure was correct. She disinfected the wound, checked for damage to the nerves and tendons, and used medical chakra only after confirming that no foreign material remained.
Approval entered Shizune's eyes.
Rin had not received years of specialized medical training, yet her fundamentals were already stable. For someone her age, that was enough to meet the minimum requirements of the Advanced Medical Class.
Then Shizune turned toward Ren.
Her expression changed.
Ren had already cleaned the thigh wound and removed the final fragment of contaminated cloth. His movements were efficient, and the amount of pressure he applied was precise enough to control the bleeding without damaging the surrounding tissue.
Those details were impressive, but they were not what surprised her.
A soft green light surrounded Ren's palms.
His medical chakra flowed into the patient's leg, stimulating the torn muscle fibres and damaged vessels. The technique itself was unmistakable.
It was the most basic Healing Technique.
However, the result was anything but basic.
Even after Ren's hands moved away from one section of the injury, traces of healing chakra remained inside the tissue. Rather than dispersing, they continued activating the patient's cells and guiding the damaged fibres back together.
The wound was healing without direct contact.
Shizune leaned closer, wondering if she had misunderstood what she was seeing. When the residual chakra continued working, shock spread across her face.
"Lady Tsunade!" she called. "Please look at this. There's a continuous cell-activation effect inside the wound."
Tsunade's body became still.
Her gaze shifted toward the blood around the patient's thigh.
For the briefest moment, her face lost some of its colour.
Ren noticed.
Tsunade's hemophobia was one of Konoha's most closely guarded secrets. Only a small number of people—including Hiruzen, Jiraiya, Orochimaru, and Shizune—knew how severely the sight of blood affected her.
If Konoha's enemies learned that its greatest medical-nin could freeze upon seeing blood, they would exploit it without hesitation. The secret also had to be protected to preserve confidence in the village's medical forces.
Tsunade pressed her fingernails into her upper arm through the sleeve of her haori. The sharp pain helped anchor her attention.
She approached the bed slowly, focusing on Ren's chakra rather than the blood surrounding the wound.
"What did you find?" she asked.
Shizune pointed toward the tissue Ren had already treated. "The Healing Technique ended several moments ago, but the cells are still responding. The residual chakra isn't fading."
Tsunade examined the wound.
Her earlier irritation vanished.
She bent slightly, studying how Ren's chakra had attached itself to the damaged tissue. The effect was extremely subtle, but to someone with Tsunade's knowledge, it was impossible to miss.
The residual energy did not merely accelerate surface healing.
It penetrated deeper, stimulating torn muscle fibres, reconnecting small blood vessels, and guiding the tissue through a controlled process of self-repair.
Tsunade's eyes narrowed.
"This continuous activation… and the depth of the repair…" She looked directly at Ren. "Brat, what technique are you using?"
"The Healing Technique."
"Don't play games with me." Tsunade's voice sharpened. "I know what the Healing Technique looks like. An ordinary application cannot continue affecting tissue after the user withdraws their chakra."
Ren took a measured breath, but his hands did not stop moving.
"Lady Tsunade, I would disagree with one part of that statement."
Tsunade raised an eyebrow. "Which part?"
"The Healing Technique isn't ordinary."
The entire ward seemed to become quieter.
Ren continued guiding medical chakra into the patient's leg while explaining himself.
"It may be basic, but almost every advanced medical technique begins with the same principles—precise chakra control, cellular activation, and an understanding of the human body."
He glanced down at the green light surrounding his hands.
"The Healing Technique is like a mother. She gives birth to countless advanced medical ninjutsu and quietly supports them, yet no one remembers her once they learn something more impressive."
Tsunade stared at him.
Shizune blinked twice.
Even Rin briefly lost concentration and looked toward Ren.
"Did you just compare a medical technique to your mother?" Tsunade asked.
Ren maintained a perfectly serious expression. "I said its role is similar to that of a mother."
"That doesn't make it sound less strange."
"Perhaps not. But I genuinely believe that a foundational technique should be capable of far more than most people assume."
A notification appeared in front of Ren.
[Healing Technique: Little Ren, you child… Did you really call me "Mom" just to make me happy?]
[Healing Technique Favorability +3]
[Current Favorability: 78/100—Attachment]
Ren nearly lost control of his chakra.
His speech had partly been intended to please the Healing Technique, but the praise was also sincere. Of all the techniques in his Strategy List, Healing Technique was the only one that actively restored his body and protected the lives of others.
Its position in Ren's heart was second only to the Three Basic Academy Techniques.
He had not expected the system to interpret his words so literally.
Another series of notifications appeared.
[Special Event Keyword Detected: Mother]
[Limited-Time Bond Mission Triggered]
[Healing Technique is the most fundamental medical ninjutsu. Although she is gentle and never competes for attention, she secretly wishes to prove her value to the world.]
[Mission Requirement: Personally treat 100 patients using Healing Technique.]
[Will you fulfil her wish?]
Ren hesitated for less than a second.
"Yes."
He accepted the mission immediately.
The system might have questionable tastes, but Ren refused to reject a useful opportunity simply because its presentation was embarrassing.
[Limited-Time Bond Mission Accepted]
[Progress: 0/100]
[Healing Technique: All right. This time, "Mom" will help you. Let that woman see what the most ordinary medical ninjutsu can accomplish.]
Before Ren could complain about the nickname, a strange rhythm pulsed through his chakra network.
Warmth spread from his chest into his shoulders, arms, and hands. The Healing Technique seemed to awaken inside him, taking control of the chakra flow and refining it beyond what Ren could currently achieve alone.
A rich emerald light poured from his palms.
Shizune instinctively took a step back.
The chakra settled over the patient's mangled thigh like a warm spring breeze. Instead of forcing the damaged tissue together, it separated into countless fine streams.
Each strand performed a different task.
Some sealed ruptured vessels. Others aligned severed muscle fibres, cleared damaged cells, or reduced inflammation around the wound.
It resembled an impossibly precise loom weaving a torn piece of cloth back together.
The exposed muscle tissue began to move.
Slowly at first, then with visible speed, the curled fibres loosened and stretched toward one another. Tiny blood vessels reconnected, the bleeding diminished, and healthy colour returned to the surrounding skin.
The patient's strained breathing gradually eased.
The most basic Healing Technique produced results comparable to those of an experienced medical chūnin.
Even more astonishingly, Ren did not feel an excessive drain on his chakra.
The technique itself appeared to be guiding and supporting him. Every unit of chakra was used efficiently, with almost nothing wasted.
Tsunade stared at his hands.
Her gaze became so intense that Ren could practically feel it against his skin.
She watched his chakra pathways, the precision of his cellular activation, and the residual Healing Brand settling inside the patient's tissue.
There was no forbidden technique.
No bloodline limit.
No hidden medical tool.
It was genuinely the Healing Technique, cultivated far beyond the level anyone expected from a child.
A genius.
The brat in front of her was unquestionably a medical genius.
Hebiji's recommendation had not exaggerated Ren's ability. If anything, his description had been too conservative.
If Ren could achieve this with the Healing Technique, what would happen after he learned the Mystical Palm Technique? What could he accomplish after studying poisons, surgery, cellular regeneration, or the human chakra network?
With proper guidance, he might eventually become one of the pillars of Konoha's medical division.
Tsunade had withdrawn from frontline medical work after the previous war. The deaths she had endured—and the hemophobia that followed—had left her increasingly disillusioned with both Konoha and the shinobi system.
For the past two years, she had even considered leaving the village with Shizune.
But if she could cultivate someone capable of carrying Konoha's medical legacy before she left, perhaps she would not feel as though she had abandoned everything created by her grandfather and teacher.
Tsunade glanced toward Rin.
Rin's performance was less astonishing, but her work remained careful and technically correct. She had finished closing the lacerations without causing additional damage, and her patient's condition was stable.
That was enough.
"Stop," Tsunade ordered.
Ren immediately withdrew his hands. The Healing Brand remained inside the wound, continuing its work.
Rin completed her final bandage and stepped back.
Tsunade inspected both patients before facing the two young shinobi.
"Rin Nohara," she said, "your fundamentals are solid, and you remained composed despite being watched. You still lack experience, but that can be corrected."
Rin held her breath.
"You qualify for a probationary place in the Advanced Medical Class."
Rin's eyes widened with joy. She bowed deeply. "Thank you, Lady Tsunade! I'll work hard!"
"You'd better. I don't tolerate careless students."
Tsunade then turned toward Ren.
"As for you…"
Ren met her gaze.
"You're strange," Tsunade said.
Shizune pressed her lips together, barely concealing a smile.
"But you do possess talent." Tsunade crossed her arms. "More talent than Hebiji's letter suggested."
She glanced at the patient's rapidly stabilizing wound.
"The Healing Technique is the foundation of medical ninjutsu. Anyone who can cultivate that foundation to this degree deserves to see what lies beyond it."
Tsunade made her decision.
"Starting tomorrow, both of you will report here at nine-thirty every morning."
Rin's face lit up.
Tsunade pointed at Ren before he could celebrate. "Missions outside the village are the only acceptable excuse for absence. If you're late, I'll throw you out myself."
"We understand," Ren answered.
"One more thing." Tsunade's eyes narrowed. "Hebiji recommended you for the class, but your Healing Brand is unusual enough that I'll be supervising part of your training personally."
Ren's heartbeat quickened.
Direct access to Tsunade was exactly what he wanted.
She turned back toward the wounded shinobi, but a faint smile appeared at the corner of her mouth.
"Let's find out how far that so-called 'mother' of yours can really go."