"For the sake of Konoha? Hah! Well said!"
In the Hokage's office, Sarutobi Hiruzen laughed heartily. There was no trace of anger in his voice. "If there were more people like him, I might be able to get away with working only half-days."
Kakashi remained silent.
Hiruzen glanced at him, his smile slowly fading into a serious expression. "What is the situation with the Uchiha? Is there any news on Shisui's whereabouts?"
"None." Kakashi shook his head and began his report. "The consensus within the Uchiha clan is that Shisui is dead. Itachi's mental state was deteriorating rapidly, but there seems to have been a shift after his contact with Masahiko Yagyu a few days ago…"
Hiruzen looked thoughtful. "Why did Masahiko approach Itachi?"
"I heard it was at Sasuke's request. Furthermore, Masahiko and Shisui were classmates and had exchanged pointers in the past, so he went to pay his respects," Kakashi answered dutifully. "Based on brief surveillance by my subordinates, it appears he truly just wanted to help Sasuke."
Hiruzen nodded gently but remained silent for a long moment. He tapped his pipe against the ashtray, lost in thought. Finally, he spoke, "Continue monitoring the Uchiha. Their situation is precarious. We must prepare for the worst."
"Yes, sir."
Kakashi bowed, preparing to leave.
"Kakashi, wait a moment."
"Hmm?" Kakashi turned back to face the Hokage.
Hiruzen seemed hesitant, as if weighing his words. Finally, he closed his eyes and sighed. "Do not let past events cloud your judgment. For the sake of Konoha, there are things we all must do, however difficult."
Kakashi stood in silence for a few seconds before nodding slightly. "I understand."
He walked out of the office. Just as he was about to return to the Anbu headquarters, he heard footsteps ascending the stairs. Relying on his instincts, he immediately flickered into the shadows to conceal himself.
Moments later, a man dressed in medical ninja attire arrived at the Hokage's door.
It was Gozan, a Jōnin of the Medical Research Department.
"Hokage-sama, this is an employment invitation for our Research Department. Because the candidate is somewhat special, we require your approval."
"Oh?" Hiruzen took the document, scanning it briefly before raising an eyebrow.
Masahiko Yagyu again?
He sat up straighter, reading the invitation carefully. "I recall he has only just begun dabbling in the medical field. Is he truly this important to your work?"
"Masahiko-kun's technique is preliminarily complete. The next step involves fusion with Water Style. While difficult, I believe the transition will be manageable for him," Gozan answered frankly.
Hiruzen paused for a moment, absorbing the information, then picked up his brush and signed the document.
"He may serve in a part-time capacity. Issue his salary according to the standard for a Jōnin specialist."
"Yes, sir!"
The Next Day. Konoha Hospital, Research Department.
"So, you're saying I have Jōnin-level clearance within the Research Department?" Masahiko asked, genuinely surprised.
Gozan nodded with a smile. "That's correct. Hokage-sama authorized it himself."
"In that case, may I look up the hospital's research regarding Kekkei Genkai diseases?" Masahiko asked. He then proceeded to explain the situation regarding his student, Yakumo Kurama.
"I suspect these bloodline illnesses are linked to an imbalance in physical functions or power output. My current adjustments for her are heading in that direction."
"Bloodline diseases are complex. The Kurama Clan…" Gozan recalled the data and nodded. "We have one case file. But before you see it, you'll need to sign a confidentiality agreement."
"Understood."
Masahiko nodded and signed his name without hesitation.
Investigating the Kurama clan's illness was merely a pretext.
The file was thin—just a single booklet with scant information. Konoha's research into the spiritual and mental realm was not particularly deep. The notes mostly described the patient's extreme personality and suspected anti-social tendencies. The final outcome wasn't recorded, but with a little imagination, one could guess it didn't end well.
Masahiko pretended to ponder over the file before looking up at Gozan. "This is too little. Is there research on any other Kekkei Genkai diseases?"
"Others… are quite rare," Gozan said, shaking his head.
"What about bloodline illnesses from other villages? Perhaps there's cross-reference value," Masahiko said, feigning a frown of concern.
Gozan thought hard, his expression twisting into one of distaste. "We do have some data on the Kaguya Clan's bloodline disease. It was seized during the war. But that bunch of lunatics never did any proper research. Their notes are a complete mess."
"Let me see them." Masahiko suppressed his rising anticipation.
Gozan couldn't help but sigh in admiration. "Teachers as serious, responsible, and kind-hearted as you are truly a rare breed these days."
"Kindness is only part of it. On the other hand… she is actually quite dangerous," Masahiko replied vaguely.
Gozan nodded knowingly. He had seen the files; he knew the Kurama clan's Kekkei Genkai—and their illness—were terrifyingly erratic. That Masahiko was willing to go to such lengths only made Gozan admire him more.
He walked to the archive's secure vault and, after some rummaging, pulled several booklets from a dusty corner.
It was just as Gozan had said. The Kaguya Clan were battle-crazed warmongers. They didn't know the meaning of the word 'research.' The writings were scattered and disjointed, reading more like the diaries of madmen than medical journals.
From the diaries, it was clear the morbidity rate was quite high.
But, without exception—they were all the clan's "strongest warriors."
Masahiko narrowed his eyes thoughtfully. "Gozan-senpai, regarding this type of bloodline disease… is it possible that the more they use their power, the more likely they are to fall ill?"
"We can't generalize. In the case of the Shikotsumyaku, our hypothesis is that it might be related to their habit of extracting and retracting bones, or perhaps the rapid skeletal regeneration places an undue burden on their internal organs and bodily functions…"
Gozan shared the Medical Corps' theories. "Whereas the Kurama Clan's issues seem to be spiritual mutations… essentially, the mental illness you mentioned."
"I see. What about Dōjutsu types?" Masahiko asked.
Gozan hesitated, then coughed lightly. "Let's… skip that topic."
Masahiko didn't press. In truth, he had already formed a plan in his mind.
Viewing it holistically, the issue with the Shikotsumyaku lay in improper usage or abuse of the Kekkei Genkai, leading to systemic failure.
He needed to pioneer a new method of usage.
'Perhaps I can reference the All-Killing Ash Bones (Tomogoroshi no Haikotsu). Kaguya Ōtsutsuki's technique is a Kekkei Mōra—a higher order of existence. While Shikotsumyaku cannot perfectly replicate it, I can certainly learn from its underlying principles…'
Masahiko wasn't like those fools in the Kaguya clan. He wouldn't be complacent, blindly using the technique exactly as it had been handed down.
Having solidified his train of thought, Masahiko reined in his focus.
"Thank you, Gozan-senpai. I'll think this over and try to put together a treatment plan."
"I've heard about Yakumo's condition. Honestly, she's already doing much better thanks to you," Gozan said earnestly.
Masahiko shook his head. "She is currently very dependent on Kurenai-senpai and myself. I still worry… in the ninja profession, no one knows what tomorrow holds."
Hearing this, Gozan sighed deeply and nodded.
Ninjas danced with death. Teachers and doctors were logistical personnel and relatively safe, but as Masahiko's strength grew, he wouldn't remain just a teacher forever. The future was unpredictable.
Masahiko found an excuse to bid Gozan farewell. Upon returning home, he immediately entered the [Performance Instance].
The dungeon was the best possible training ground.
Inside the simulation—
Whoosh!
Masahiko exploded with full speed, his figure vanishing from his starting position instantly.
The [Smart Projection: Kakashi] narrowed his eyes sharply.
Clang!
Kakashi drew his blade to block, but the sheer force of Masahiko's strike sent a shockwave up his arm, numbing the webbing between his thumb and forefinger.
Before Kakashi could recover, the figure in front of him faded—an afterimage. Three iterations of Masahiko leaped from three different directions, striking simultaneously.
'Clones in mid-air… difficult to track.'
Kakashi had no choice but to escalate.
Lightning Style: Lightning Beast Tracking Fang!
But this time—
Two of the "Masahikos" clasped their hands together. Each clone lent one hand to perform a coordinated seal, while their free hands slapped the ground.
A towering wave of water erupted, insulating them from the lightning.
Bang!
The third Masahiko landed a heavy kick, sending Kakashi flying. However, the silver-haired jōnin burst into smoke mid-air—a Shadow Clone.
A split second later, the real Kakashi erupted from the earth below, his blade thrusting upward. He missed Masahiko's vitals by a hair's breadth, the steel grazing Masahiko's side.
Masahiko's hands blurred into seals. A semi-transparent sphere of high-density water formed instantly, sealing the wound.
Without pausing, he launched another offensive.
A few seconds later, he was injured again.
Masahiko frowned, retreating to a safe distance.
'My physical stats have increased too quickly. I'm not adapted to this speed and power yet; I can't control it perfectly…'
Again!
He needed to keep fighting. He had to attempt to mobilize the power of the Shikotsumyaku during high-intensity combat, forcing the dormant potential within his bloodline to awaken.