By the time Uchiha Yoru finished a full day of administrative work and absorbed the backlash from dispelling his shadow clones, exhaustion pressed down on him like wet armor.
What he didn't know was that ANBU had already finished laying a trap with his name written neatly at the center.
Underground Research Facility, Konoha
Yoru rubbed his temples as he stepped inside.
Morning had been paperwork. Afternoon had been controlled rest, bracing himself for the mental recoil of shadow clone dispersal. Even now, the fatigue lingered. It wasn't hard to see why only monsters like Naruto could abuse that technique without consequence. Mental recovery alone filtered out ninety percent of shinobi.
Orochimaru sensed his arrival and looked up, lips curling into a hoarse smile.
"Heh… Yoru-kun. Come take a look at my latest work."
Without waiting for a reply, Orochimaru launched into explanation.
"Whether it's the Living Corpse Reincarnation or Edo Tensei, the foundation is the same: massive chakra reserves. Just like senjutsu. Without quantity, nothing functions."
As Yoru approached the experiment table, his brow furrowed.
A restrained prisoner lay there, body writhing, black markings spreading across his skin like ink in water. The man groaned, teeth chattering, barely conscious.
"This is…?" Yoru asked, already knowing the answer.
Orochimaru's eyes gleamed.
"Senjutsu."
Yoru frowned, playing along."Natural energy?"
Orochimaru nodded, clearly pleased.
"Whether the Sage of Six Paths truly existed is debatable. But senjutsu does. The Fire Temple has records. The great summoning regions as well. Ryūchi Cave most of all."
Yoru responded calmly, as if recalling text from memory.
"Normal chakra is formed by balancing physical and spiritual energy. Senjutsu chakra adds natural energy into the mix. Techniques fueled by it become senjutsu—stronger, sharper, with heightened perception."
Orochimaru laughed softly."As expected. Most shinobi never read anything outside jutsu scrolls. You're different."
He continued, excitement bleeding through his voice.
"Senjutsu amplifies techniques severalfold. It enhances sensory ability beyond normal limits. But the barrier to entry is absurd. Massive chakra reserves. Years of conditioning."
He leaned closer to the experiment table.
"But I discovered something else. A bloodline capable of naturally absorbing natural energy."
Yoru's eyes narrowed slightly.
"In the north, we found a boy," Orochimaru said. "When exposed to dense natural energy, he undergoes partial sage transformation. Unstable. Violent. But genuine."
Orochimaru gestured at the writhing subject.
"This curse mark is derived from that ability."
So this was it. The origin.
The Curse Seal.
Yoru inclined his head."Does natural energy interact with the soul?"
Orochimaru's smile widened.
"Exactly. It corrodes spiritual energy. Alters the will. Enhances power while eroding resistance. Natural energy is… far deeper than we understand."
Yoru understood immediately.
That was why Sasuke's Curse Seal worked. Not temptation. Indoctrination.
He set aside the thought and produced a scroll.
"This is from Hyūga Hizashi. The Caged Bird seal records. And funding."
Orochimaru accepted them with mild interest, chuckling.
"The Hyūga branch family has struggled with that seal for generations. Don't expect quick results."
Despite the words, he took the scroll anyway.
Between two forbidden reincarnation techniques, Root's Wood Release revival, and now curse seal research, Orochimaru's plate was overflowing. Only in the shinobi world could one man survive this workload.
"Sensei," Yoru said lightly, "the Caged Bird is a curse seal, but it's also derived from fuinjutsu. Could it be suppressed… by another seal?"
Orochimaru shook his head.
"Fuinjutsu is not like elemental ninjutsu. Talent isn't enough. It demands extreme precision. You can study it, but don't sink too deep."
Still, he opened his mouth.
A snake slid out.
Then another.
Finally, a massive scroll emerged, absurdly larger than the serpent itself.
"These are my collected sealing techniques," Orochimaru said. "Learn a few. Survival matters more than elegance. Strength enough to avoid death—that's the prerequisite for ambition."
Yoru smiled faintly and accepted it.
That philosophy explained everything about Orochimaru. His jutsu weren't elegant. They were grotesque. Redundant. Impossible to kill.
And they worked.
Night fell.
Outside an imposing Uchiha residence, Uzuki Yūgao stood frozen.
This time, there was no pretense. No acting. Her chest felt tight, thoughts spiraling.
Was she really going through with this?
Nakata Mika stood beside her, voice unsteady.
"This is the captain's home… He hasn't returned yet."
She hesitated, then forced a bitter smile.
"Yūgao. You can still turn back. Sell your apartment. Your savings. Would it cover even half?"
Yūgao smiled weakly.
"My parents were civilians. The apartment might sell for fifty thousand. With savings… maybe five hundred thousand total."
She swallowed.
"The debt is three million."
Mika exhaled slowly.
"I don't know if this is right," she said quietly. "Dragging you into this…"
She met Yūgao's eyes.
"But listen carefully."
"If you cross this line, you lose something you never get back. Your dignity."
"If it's just for money, don't get pregnant. Set terms. With clan backing, two or three years is all it takes before they let go. Then forget it. Live your life."
Yūgao lowered her head, lips trembling into a strained smile.
"Do you really think someone forgets something like this?"
Mika sighed.
"Yoru-sama is a decent man. The Uchiha are proud. They don't mistreat women."
She stepped closer, gently tucking Yūgao's purple hair behind her ear.
"Being attached to a powerful man isn't shameful. Strength attracts followers. This world doesn't change."
Then, quietly:
"I didn't become a second wife because of him. I refused because of my child."
Her eyes hardened.
"My husband died in the war. I won't let the Nakata name end with me."
Yūgao tried to speak. Couldn't.
Mika shook her head gently.
"You don't need to thank me. If you regret this, turn back now."
She turned and walked away, disappearing down the moonlit street.
The house lights turned on.
Yoru returned late.
Too late.
He vaulted silently across rooftops, landed outside his residence—and froze.
The lights were on.
Someone was inside.
His eyes sharpened. Three tomoe spun into place as the Sharingan flared crimson. His hand slid to the hilt of the Kusanagi blade. Venomous snakes crept from his sleeve.
Clan head? No.
Elder? Unlikely.
Hyūga Hizashi? Impossible.
Yoru exhaled slowly.
Whoever it was… had already crossed his threshold.