While the two medical-nin arranged their demonstration materials, Ren took a sheet of scratch paper and drew a simplified diagram for Rin.
He sketched the stomach, spleen, liver, and the major vessels linking them. The drawing was rough, but it made the portal circulation far easier to understand than the crowded anatomical chart at the front of the classroom.
Rin followed each line with the tip of her pen.
Her eyes brightened.
"Oh! So the hepatic portal vein carries the blood into the liver before it returns to the heart."
"Exactly. The liver processes what arrives from the digestive organs before the blood enters general circulation."
Rin quickly corrected her notes.
"Thank you, Ren."
Then she paused.
Her pen stopped above the page as she slowly looked up at him.
"Wait. How do you remember all this so clearly? You barely took any notes."
Momogi was still watching them.
"That's what I want to know," he said. "I've attended medical training for more than half a year, and I couldn't have explained that as clearly as you did."
Ren placed the pencil beside the sketch.
"My mother works at Konoha Library. I've spent a lot of time reading there since I was little."
"That explains knowing the terms," Momogi said. "It doesn't explain understanding them."
"I only understand the theory." Ren shrugged. "I've never treated a real patient. Knowing what a blood vessel is called and stopping it from bleeding are completely different abilities."
Momogi considered the answer.
"At least you know the difference. Some students memorize two medical books and start acting like qualified physicians."
Obito, who had been excluded from the conversation, finally found an opening.
"What's so difficult about it? It's only the route blood takes through the body. I understood it too."
Rin turned toward him.
"Then what does the splenic vein join before forming the portal vein?"
Obito froze.
His gaze shifted toward the ceiling.
"The… other vein."
"Which other vein?"
"The important one."
Momogi covered his mouth, but a laugh escaped anyway.
Obito's face reddened.
"I understood the general idea."
Rin's expression became serious.
"You weren't listening. You spent most of the lesson staring away from the board."
"I wasn't staring away."
He had been looking toward Rin for much of the lecture, which was technically true but not a useful defense.
"Basic knowledge matters," she continued. "If you don't understand the body, you won't know what an injury has damaged or how to help someone. You can't stop trying whenever a lesson becomes difficult."
Obito shrank slightly beneath her disappointment.
"I'll listen during the next class."
"You promised to listen during this one."
"I'll listen twice as carefully."
Rin sighed.
Before she could continue, the first instructor called the class back to order.
The white cloth was removed from the metal tray, revealing preserved anatomical specimens and several models used to demonstrate the position of internal organs. The second medical-nin maintained a faint layer of green chakra around the tray, preventing contamination and stabilizing the material.
Ren watched closely.
The system notification remained incomplete.
[Potential medical technique observed.]
[Encounter conditions not satisfied.]
The chakra control involved was real, but the technique was being used only as support. Ren could not identify its full structure, purpose, or activation process.
No target was added.
The practical segment lasted another twenty minutes. The instructor used the specimens to show how penetrating wounds could damage multiple organs despite leaving only a small opening on the surface.
By the time the lesson ended, several students looked pale.
The instructor covered the tray again.
"Remember this: the wound you can see is not always the injury that kills the patient. Never judge internal damage solely by the size of the external opening."
He gathered his notes and left with the assisting medical-nin.
A fifteen-minute break began before the next lecturer arrived.
Rin remained at her desk, reorganizing everything she had written. Momogi turned several pages in the anatomy book, while Obito attempted to copy the most important points from Rin's notes without making it obvious.
Ren stood.
"I'm going to look around."
Rin glanced up. "Don't get lost."
"I'll stay on this floor."
He stepped into the corridor.
Part of his motivation was practical. Konoha Hospital was large, and learning its layout could prove useful if he or someone close to him needed treatment.
The other reason was the system.
Medical-nin moved constantly between rooms. If Ren happened to witness one of them using a complete technique, he might trigger an encounter before the next class even began.
He walked past the reception station and several wards.
Through one open doorway, he saw a nurse changing a bandage. In another room, a medical-nin examined an X-ray-like chakra image produced on a transparent sheet.
None of the observations lasted long enough for the system to react.
Ren continued toward the end of the corridor.
Voices drifted from a partially open staff room.
"…another group arrived from the southwestern border last night."
Ren slowed.
Two medical-nin in white coats stood inside. Both appeared exhausted.
"The southwestern border?" one asked. "Near the Land of Earth?"
"That's what I heard. Three wounded Chūnin and seven Genin. One of them lost an arm."
"Were they attacked by Iwagakure?"
"No one will say. That kind of intelligence is above our rank."
The first medic looked toward the floor.
"We've barely had a few years of peace."
His colleague leaned against a cabinet.
"If war starts again, these wards won't hold only ten wounded shinobi. We'll have hundreds. Maybe thousands."
Neither spoke for a moment.
Ren remained outside the doorway, listening.
A third medical-nin approached from the opposite end of the corridor. He was younger than the other two and carried a stack of folded sheets.
"You're both worrying too much," he said. "We're shinobi. People die on missions every day."
The older medic frowned. "That doesn't make it meaningless."
"I didn't say that." The younger man shifted the sheets against his shoulder. "I'm only saying there's no point fearing what we can't prevent."
He smiled with forced carelessness.
"Death is just a cool summer night offering endless, worry-free sleep."
The room became quiet.
The older medic stepped toward him.
"Would you say that if you had buried family during the last war?"
The younger man's smile disappeared.
"Why are you making this personal?"
"Because death is personal."
"I was trying to lighten the mood."
"You failed."
The argument rapidly grew louder.
When the older medic shoved the younger man's shoulder, a head nurse appeared from the adjoining room.
"If either of you damages hospital equipment, I'll assign you both to bedpan duty for a month!"
The confrontation ended immediately.
Ren silently retreated before anyone noticed him.
The comedy of their argument could not erase what he had overheard.
Wounded shinobi were already arriving from the border near the Land of Earth.
Kumogakure was moving in the north.
Pressure was building around the Land of Fire from multiple directions.
Ren knew the Third Great Ninja War would begin within the next few years. The Battle of Kannabi Bridge—where Obito was believed to have died—would occur near the conflict's end.
But the exact beginning of the war had never been clearly established in the story he remembered.
There would be border incidents, retaliatory missions, covert operations, and shifting alliances. The Five Great Nations would drag smaller countries into their struggle until no one could identify a single clean starting point.
Perhaps the war had already begun.
Perhaps people simply had not named it yet.
A colder thought entered Ren's mind.
His father was stationed at a border outpost.
The assignment had begun as a way to earn additional pay for their family. Now that same posting placed him directly in the path of an approaching war.
Ren had received no recent news.
No casualty notice had arrived either, but silence offered little comfort in a shinobi village. Missions were classified, letters were delayed, and a family might wait weeks before being told that someone would never return.
"Is he still safe?"
Ren's earlier confidence faded.
For all the abilities granted by the system, he remained an academy student trapped inside Konoha. He did not even know which border post his father currently occupied.
If war erupted tomorrow, Ren could do nothing to reach him.
His hands slowly clenched.
That helplessness was exactly why he needed strength.
Not for rankings.
Not for admiration.
Not even to rewrite the future of famous characters.
He needed enough power to protect his own family.
The coming war was no longer a distant event from a story. His father might already be standing on its front line.
Ren returned to the classroom before the break ended.
Rin was still correcting her notes. Momogi had opened the pharmacology section of the textbook, while Obito sat unnaturally straight and pretended that he had been studying the entire time.
Ren resumed his seat.
Rin noticed the change in his expression.
"Did something happen?"
"Nothing important."
She did not appear convinced, but the classroom door opened before she could question him.
A blonde woman entered.
She wore black-rimmed glasses and carried a covered basket containing two small rabbits. Her clothing was simple, and her movements possessed the quiet efficiency of an experienced medical-nin.
A gentle warmth seemed to follow her into the room.
Ren recognized her immediately.
Nonō Yakushi.
Before becoming the director of Konoha's orphanage, Nonō had served as one of Root's most talented intelligence agents. She was a skilled spy, an exceptional medical-nin, and one of the few people capable of making a young Kabuto feel that he had found a home.
At this point in history, she had already distanced herself from Root and dedicated most of her life to supporting the orphanage.
Kabuto had probably not arrived there yet.
Nonō placed the basket on the front table and turned toward the class.
"Good morning. My name is Nonō Yakushi. I currently manage the Konoha Orphanage and lecture here when the hospital needs additional instructors."
Her voice was calm and soothing.
"I'll be teaching the second session today: introductory pharmacology."
Nonō Yakushi's arrival changed the atmosphere of the entire classroom.
Even Obito raised his head and listened.
Nonō began with the properties of common medicinal plants, then explained how different ingredients could be processed into antiseptics, pain relievers, clotting agents, and antidote bases.
Her lesson was clearer than the earlier anatomy lecture. She used simple examples, compared ingredients by smell and color, and repeatedly explained what could be substituted when a specific herb was unavailable in the field.
Ren quickly understood why children at the orphanage trusted her.
She did not merely teach information.
She made people feel safe enough to admit when they did not understand.
After introducing several medicines, Nonō uncovered the basket.
The two rabbits inside were calm and drowsy, having already been lightly sedated.
"We'll use Regenerative Ointment as our example," she explained. "This medicine promotes clotting and gently stimulates tissue repair. Its effect is slower than medical ninjutsu, but it can be applied by anyone and requires no chakra."
She placed the first rabbit on a padded surface and made a small, controlled incision on its hind leg.
Several students leaned closer.
Nonō applied a measured amount of ointment. Bleeding slowed almost immediately, and within several minutes, a thin protective layer formed over the wound.
"This is useful for shallow injuries," she said. "But medicine alone may be too slow when a patient is losing blood rapidly."
She prepared the second rabbit.
This time, after creating an equally small incision, she set the blade aside and held one hand above the wound.
Green chakra gathered around her fingers.
The glow was soft, warm, and astonishingly stable.
Everyone rose from their seats and moved toward the demonstration table.
Ren stood beside Rin and Momogi, his eyes fixed on Nonō's hand.
The green light flowed into the damaged tissue. The edges of the wound drew together, new cells forming at a speed visible to the naked eye.
The rabbit's breathing remained calm.
The incision closed.
A powerful chime rang inside Ren's mind.
[High-quality potential target detected.]
[Limited-Time Encounter Mission activated.]
A new figure appeared within the emerald glow—a gentle woman formed from healing light, her presence carrying the warmth of spring sunlight.
[Potential Target: Healing Technique]
[Location: Konoha Hospital Pharmacology Classroom]
[You have encountered a mysterious figure whose touch restores damaged flesh and eases pain. Her presence offers peace amid suffering and hope in the shadow of death.]
[Will you establish an initial connection?]
[Yes / No]
Ren's eyes sharpened.
The system had finally recognized his first medical ninjutsu.