Chapter 3
The Zen'in estate was nestled at the foot of Mount Hiei, its cascading eaves dusted with fresh snow.
Five-year-old Zen'in Genji woke from his sleep.
Not a nightmare. The reality was more absurd than any nightmare. A moment ago, he had been on a national highway in the 21st century, struck by a golden holy relic, his consciousness shattered by searing pain. The next moment, he woke up in the body of a child, with ancient Japanese whispers in his ears and a dimly lit Japanese-style room before his eyes.
"Young Master Genji, it's time for your morning lessons." A maid's voice came through the paper door.
It took him three months to accept reality: he had crossed over and become the child of an ancient aristocratic family in the land of cherry blossoms. It took another two years to piece together an even more frightening truth from fragmented conversations among the clan elders—this was not an ordinary historical world.
There existed "cursed energy," "jujutsu," and monsters called "curses."
This was the world of Jujutsu Kaisen, but an ancient version.
On the night of his fifth birthday, he saw ten shadows in the snow. When they awakened, the clan elders trembled and fell to their knees, repeating the words "Ten Shadows Technique."
The divine child of the Zen'in clan had been born.
---
At thirteen, Zen'in Genji stood in the courtyard. Shadows writhed like living creatures beneath his feet. Jade Dog Black and Jade Dog White emerged from the darkness and nuzzled affectionately against his calves.
"Brother."
He turned. Zen'in Sei stood in the corridor. Genji's younger twin brother had already grown strong, like a young samurai.
Zero cursed energy. Heavenly Restriction. Born as the "brother's accessory" according to the clan—the second half of Zen'in Genji's "complete existence."
Genji walked over and ruffled his brother's hair. This action made the surrounding servants' expressions flicker. In the Zen'in clan, a Heavenly Restriction user was not worthy of standing equal with a sorcerer, let alone being treated with such closeness.
"Sei," Genji said, his voice calm but loud enough for everyone to hear. "Cursed energy isn't everything. You have everything you need."
He remembered how harsh Fushiguro's situation had been in the original story. Since his younger brother was born with a Heavenly Restriction, he would become the strongest Heavenly Restriction user—not a sacrifice to the Zen'in clan's decaying ideology.
That night, he declared before the entire clan assembly: Zen'in Sei was no one's slave. He was Genji's blood relative and a member of the Zen'in family.
Resistance surged like a tide—until the shadows beneath Genji suddenly expanded, covering the entire council hall.
His shikigami did not appear. But the overwhelming pressure of his cursed energy silenced every voice.
"My word is final," said the thirteen-year-old.
---
Genji first met Sukuna in the ruins of a village at the foot of Mount Tamba.
Four arms. Two faces. Crimson lines crawling across his entire body. The legendary "Ryomen Sukuna" sat beside a corpse, tearing into flesh and blood as if tasting a delicacy. A thick, oppressive cursed energy hung in the air.
"That's ugly," Genji said.
Sukuna's four eyes turned simultaneously.
The next moment, an invisible slash tore through the air—but stopped three feet from Genji, blocked by the sudden rise of the Crane shikigami's wings. Sparks flew.
"Oh?" Both of Sukuna's mouths opened at once, revealing a hideous grin. "A little brat from the Ten Shadows."
The battle lasted half an hour. Max Elephant's water surge washed away half the mountain. The Snake's poisonous miasma turned the sky purple. Sukuna's slashes carved everything around them into pieces. Finally, when Mahoraga's adaptation wheel began to turn behind Genji, Sukuna chose to retreat.
"Interesting." Before leaving, Sukuna's four eyes stared deeply at Genji. "I will come to you again, son of the Zen'in clan."
From that day on, the title of "strongest" in the Heian period had two candidates.
---
The subjugation ritual for Mahoraga was held in the shadow realm of the Zen'in clan's forbidden grounds.
Sixteen-year-old Zen'in Genji stood at the center of the ceremony, surrounded by nine shadows of his shikigami. Across from him, the massive body of Mahoraga slowly rose from the deepest darkness. The adaptation wheel began to turn.
Subjugation could not rely on outside help—that was the iron rule of the ritual. Any interference would break the ceremony.
But Zen'in Sei stood three steps behind his brother, holding a cursed tool, his cursed energy showing not a trace of wavering.
"Heavenly Restriction. Zero cursed energy. He does not count as 'another person,'" Genji had explained to the clan elders before the ceremony. "Sei is a part of me. His participation does not break the rules."
The battle was unimaginably fierce. Each of Mahoraga's attacks carried the trait of "adaptation." The eight shikigami took turns, barely holding it back.
The fight had to be short. Genji had to defeat Mahoraga as quickly as possible, before the creature adapted to all his attacks and made the subjugation ritual a failure.
Genji's cursed energy was consumed at a terrifying rate. His hunting robes were torn, staining the shadows beneath his feet with blood.
At the critical moment, it was Zen'in Sei who moved.
No cursed energy. Just pure physical strength. He crashed into the battlefield like a black lightning bolt, his long blade striking true against Mahoraga's—
Mahoraga's movements stopped.
That one breath was all Genji needed.
He killed Mahoraga.
The wheel stopped turning. Mahoraga knelt, its head lowered.
The first and only Ten Shadows user in the history of the Zen'in clan capable of fully subjugating Mahoraga had been born.
---
Thirty-six-year-old Zen'in Genji stood at the highest point of his estate, overlooking the snow-covered Kyoto.
He had been invincible for too long. Sukuna was still active, but every battle felt more like a "sparring match" between old friends—the guy shouted about wanting to kill him, but his eyes burned with excitement at facing a worthy opponent. The King of Curses versus the God of Curses. This rivalry had lasted twenty years.
Boring.
The modern soul buried deep within his heart began to stir.
He missed the internet. Convenience stores. Anime and games. That noisy but vibrant era.
This era's entertainment and culinary culture were painfully barren.
"So you want to turn yourself into a shikigami?" Zen'in Sei asked.
His younger brother was now the true head of the Zen'in clan—vigorous and decisive, a sharp contrast to the elder brother who was lazy and loved idle entertainment.
"The eleventh shikigami of the Ten Shadows Technique," Genji nodded. "I will transform all of my consciousness, memories, techniques, and physical information into the form of a shikigami and sink into the shadow realm. When a future user of the Ten Shadows Technique appears, they will be able to summon me. Then I will be able to see the world a thousand years later."
"That's risky."
"But it's interesting." Genji smiled. "Sei, live well. Lead the Zen'in clan in the direction it should go." He paused, lowering his voice. "Also... the barrier I plan to set up—a cursed energy absorption barrier covering the entire world—needs someone to maintain it. I will be gone, but the 'Guardian'... the Zen'in clan must watch over it as well. This is what I leave for future generations. A gift... or perhaps an obligation."
Zen'in Sei was silent for a long time. Finally, he simply nodded. "Understood."