The room was brightly lit, sterile to the point that the sharp scent of disinfectant hit Kakashi the moment he stepped inside. It was clean. Too clean. A space that clearly saw frequent experimentation.
"Orochimaru-sama."
Orochimaru stood alone at a worktable, studying a series of test tubes. He didn't turn around when Uchiha Yoru entered, only giving a faint nod.
"Yoru. Have Kakashi lie down first."
Kakashi lowered his head respectfully. "Yes, Orochimaru-sama."
The title of the Sannin carried weight in Konoha, second only to the Hokage himself. Even department heads treated them with caution. Strength alone had earned them that status.
Kakashi lay back on the prepared bed, his visible eye staring up at the white ceiling light. Outwardly calm, inwardly alert, he quietly took in every detail of the room.
Nearly fifteen minutes passed before Orochimaru finally set aside his notes. He turned, lips curling into his familiar rasping smile.
"A three-tomoe Sharingan," he said softly. "A fascinating thing."
The tone made Kakashi frown. His life meant little to him these days, but that eye was different. It was more precious than his own existence.
"Orochimaru-sama," Yoru said dryly from the side, "that laugh is easy to misunderstand."
Orochimaru chuckled.
At Yoru's signal, Kakashi lifted his forehead protector, revealing the permanently active Sharingan.
Orochimaru's gaze sharpened, not with greed, but with the focus of a researcher encountering a rare specimen. At this stage, bloodline limits still intrigued him, but they hadn't consumed him. A three-tomoe Sharingan was valuable, yes, but it wasn't the Mangekyō.
Yoru's hands glowed with green medical chakra as he carefully examined the eye.
"The original transplant was crude," he reported calmly. "But it was later repaired. The eye is now fully connected to Kakashi's nervous system. Functionally, it's become part of him."
Orochimaru nodded.
"A non-bloodline body bearing an awakened Sharingan," he said. "The conflict between physiology and bloodline prevents voluntary activation or deactivation. His body can't regulate it the way an Uchiha's can."
He shook his head lightly.
"This isn't unprecedented. The village has studied bloodline transplantation before."
After a brief inspection, Orochimaru lost interest. He waved a hand dismissively.
"Your suggestion was sound, Yoru. Seal it. When needed, release the seal."
Yoru smiled and removed Kakashi's forehead protector completely.
Orochimaru formed hand seals. Purple chakra flared around his fingers like tangible flame.
Sealing Technique: Five Elements Seal.
His fingers pressed down around Kakashi's left eye.
Black sealing patterns spread instantly across the skin. Kakashi clenched his teeth as discomfort surged through him. His vision blurred, the Sharingan's sharp clarity fading as if someone were dimming a light.
The three tomoe dulled.
His left eye closed on its own, a compact black seal forming on the eyelid.
Plenty of shinobi knew the Five Elements Seal. Almost none could apply it with this level of precision. Limiting a seal to a single organ required terrifying chakra control.
"This is the key," Orochimaru said, holding up a simple yellow sealing tag. "The seal restricts most chakra flow to the eye, maintaining only what's needed for viability. Think of it as dormancy. When you need it, release it with the proper hand signs."
Yoru's smile widened.
It worked. Just as he'd expected. After all, shinobi like Ao of the Mist had used seals to suppress the Byakugan. A three-tomoe Sharingan was no exception. Especially not with Orochimaru performing the seal.
Kakashi covered his left eye instinctively. The constant chakra drain vanished, as if a valve had been shut. Only a faint trickle remained.
Relief washed through him.
He stood and bowed deeply. "Thank you, Orochimaru-sama."
Orochimaru watched him with interest, licking his lips faintly.
"Hatake Kakashi," he said. "You're exceptional. Mastery of all five chakra natures. If you wish, you're welcome to work under me."
An offer.
Orochimaru admired talent, especially someone who'd become a jonin at twelve. With proper guidance, Kakashi could become something remarkable.
Kakashi said nothing. He lowered his head, silent. As the Fourth Hokage's student, accepting now would carry a very different meaning.
Orochimaru didn't press him. Instead, he turned to Yoru with a satisfied expression.
"Your research instincts may be conservative," he said, "but your ideas are the best I've seen."
Innovation mattered more than routine experimentation. Without new angles, no door to the unknown would ever open.
"Using sealing techniques to suppress bloodline dōjutsu," Orochimaru continued, pleased. "It's viable, but extremely demanding. Bloodlines are rare, compatibility is crucial, and the user must possess exceptional chakra control."
Yoru simply smiled.
Later, outside the serpent-shaped entrance hidden in the forest.
"Kakashi," Yoru said, handing him a scroll, "this is the Five Elements Seal technique. You can't rely on others forever. It's better if you can maintain it yourself."
Kakashi hesitated.
Sealing techniques were niche, difficult, and highly guarded. An A-rank technique like this wasn't something you casually gave away.
Yoru waved it off. "I'm giving it to you personally. If you really feel bad about it…"
He rubbed his fingers together.
Kakashi froze, then sighed, recognizing the familiar gesture from their academy days.
"…Fine."
He accepted the scroll. The guilt in his chest only deepened. Some things couldn't be repaid with money.
Yoru watched him leave, a faint smile on his face. One that carried more meaning than it let on.