The concept behind the Chimera Jutsu, a forbidden jutsu capable of stealing Kekkei Genkai, was born when Hiruko observed the fusion of the Uchiha clan's Sharingan with Hatake Kakashi during the Third Great Ninja War.
That moment sparked a revelation—if Kakashi could wield the Sharingan without Uchiha blood, then perhaps any Kekkei Genkai could be extracted, transplanted, and harnessed. This epiphany drove Hiruko to refine forbidden ninjutsu designed to absorb both physical and chakra-based traits from others.
"Interesting idea. Is this ninjutsu what you call the Chimera Jutsu?" Uchiha Naraku asked calmly, fingers brushing his chin, his expression unreadable.
"Exactly!" Hiruko replied, eyes burning with fervour.
"If you're just experimenting on animals, that might be tolerable... But tell me—have you considered absorbing the traits of actual shinobi? The Kekkei Genkai of other clans?"
Naraku's voice was casual as he picked up his teacup and gently blew on it.
"Kekkei Genkai, huh...?"
Hiruko's eyes widened as he processed Naraku's words. "Brilliant! You're thinking the same way I am, Lord Naraku!?"
Naraku suppressed a shiver. The mad glint in Hiruko's eyes unsettled him.
These obsessed researchers... they're terrifying. And I'm the one enabling this madness...
Still, Naraku reminded himself, "One leader's rise is built on countless sacrifices. Even if I hadn't pushed him, Hiruko would've continued. I just need the results of his forbidden knowledge."
Resolute, Naraku nodded.
"Yes. I had the same concept in mind, but I lacked someone with your expertise. Do you know why I didn't hand you over to the Hokage? Because you and I—we're alike."
Hiruko's lips curled into a smile. "It's rare to find someone who understands me like this..."
"Lord Naraku, shall we begin the experiments immediately?"
"No," Naraku replied. "I'm a member of the Konoha Military Police. Maintaining peace is my duty. We can't conduct any more experiments within the village. The Anbu will be watching."
Hiruko's brows twitched. "Then what do you suggest?"
"You can't rush perfection. I'll construct a hidden base underground, beyond the Hokage's surveillance. As for test subjects... the Konoha Prison holds plenty of suitable material. You understand, don't you?"
Hiruko beamed. "Magnificent! You truly understand what I need."
"I saw your old lab," Naraku said, coolly. "It was too basic. You need chakra monitoring tools, storage tanks, and surgical stations. All of that takes funding."
"I've completed countless A- and S-rank missions," Hiruko replied confidently. "I've saved up enough ryo to upgrade everything. That earlier lab was just a prototype."
Naraku nodded again. The Chimera Jutsu was still incomplete, but progress was undeniable. Hiruko's growing confidence was a sign of his belief in success.
As a seasoned jōnin, Hiruko had completed hundreds of A-rank and dozens of S-rank missions. Given that each S-rank task paid no less than one million Ryo, Naraku estimated his savings exceeded hundreds of millions—enough to sustain long-term research.
Even after the war, Hiruko continued operating near Konoha. His base must be extremely well hidden. If not for the elite Uchiha squad, we'd never have found it.
"No one knows about your base except the Uchiha Police. Continue your research there. Just don't harm Konoha's civilians. I'll provide funding and materials, but..."
Naraku's tone sharpened. "I expect regular updates—research logs, jutsu theory, final results. This is a mutual benefit arrangement. In return, I'll ensure your safety within Konoha's shadows."
"I couldn't ask for a better deal," Hiruko agreed readily. The Chimera Jutsu was still unproven, but Naraku's support was invaluable.
Whether or not he handed over the completed jutsu was another matter... but for now, he accepted the terms.
"Then let's seal this with a secret contract," Naraku said. "One copy each, to be held only by me. I want full access to your progress and results. Understood?"
"I understand, Lord Naraku," Hiruko said, smiling coolly.
He's probably treating me like an easy investor, Naraku thought. But I know the Chimera Jutsu will succeed. With a little investment and careful oversight, I'll be the one holding power over it.
"Riki," Naraku called.
A young Uchiha entered instantly and bowed. "Yes, sir."
"Prepare ink and parchment. Also, arrange tea for Lord Hiruko. We've had an enlightening conversation today."
"Understood!" Riki responded, bowing again before leaving to fulfil the command.
Moments later, the agreement was signed. Naraku looked over the sealed scroll and allowed himself a small smile.
"Hiruko, you can no longer remain in Konoha. The Hokage has officially marked you as an S-rank missing-nin. I'll escort you out through a weak spot in the barrier. After that, you'll be free to continue your research."
Even someone as hardened as Hiruko couldn't hide the momentary sorrow at leaving the village he'd served for over two decades.
Seeing this, Naraku offered quiet reassurance.
"Hiruko, your talents are too vast for a single village. You belong to the world beyond. Don't be sad. Once I become Hokage—if you've gained enough power—you may return."
Hiruko's eyes calmed. The Chimera Jutsu was still in development. He hadn't yet reached the height of his ambition. There were no guarantees it would work. Not yet.
For now, he was still a rogue jōnin, chasing a dream born of forbidden knowledge. But with Naraku's support, that dream was slowly becoming reality.
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