It was supposed to be just another normal day.
Renjiro was walking home from university, bag slung lazily over his shoulder, when a massive poster caught his eye.
The Shōin Tournament.
Every year, fifty competitors were chosen to fight for glory, power, and a prize decided by the tournament's creator. This year's prize, however, was unlike any before.
The winner would marry the creator's daughter.
Her name was Akari Tachibana.
Renjiro froze. His chest tightened, and he whispered her name under his breath.
His first love.
He first met Akari back in seventh grade. She was a transfer student, walking into the classroom with her long white hair tied neatly and her crimson eyes glimmering like firelight.
The class had fallen silent when she introduced herself. She looked different from everyone else—striking, otherworldly. Some kids whispered, others stared.
A few days later, spring rain poured down without warning. Most students ran for cover, but Renjiro had been late returning and ended up stuck outside without an umbrella.
That was when she appeared.
She held a small umbrella, barely big enough for one person, yet she stopped in front of him. Her damp hair clung softly to her shoulders, and her red eyes, calm and steady, met his.
"You'll catch a cold like that," she said softly.
Before he could respond, she stepped closer and handed him the umbrella. Their shoulders brushed as he took it, and for a moment, the sound of the rain faded, replaced by the quickened rhythm of his heartbeat.
Then he noticed something unusual.
Her sleeve had slipped slightly, and there, faint and shimmering like pale moonlight, was a mark on her forearm. It flickered once and vanished, as if it had never been there.
Renjiro didn't understand what he had seen. Maybe it was just the light on the wet skin… but it left a mark on his mind, sharp and unforgettable.
That was the moment he realized he liked her. Not just because she was beautiful, but because she was kind, selfless, and strangely powerful.
They never became close friends—she was popular and always surrounded by people—but she remembered his name, greeted him with a smile, and sometimes spoke to him between classes. For Renjiro, that was enough.
Now, years later, her name had appeared on that tournament poster. Not just as someone he admired, but as the prize itself.
He clenched his fists.
If fate had given him this chance, he couldn't let it slip away.
The next day, Renjiro went to the Overworld Headquarters to sign up. The hall was crowded with Shōin users, the air buzzing with energy. But he quickly realized things weren't simple.
All fifty places had already been filled.
Only four remained.
And eight challengers would fight for those last spots.
His match was scheduled for the following Sunday. One week. That was all the time he had to become strong enough to earn his place.
Long ago, a great explosion split the heavens. From that light were born two divine beings: Amateru Kojin, God of Light, and Hayashi Enma, God of Shadow.
The marks that glowed across their arms were called Shōin—living tattoos of color and shape, alive with elemental essence.
They passed these marks on, and the first disciples were born: fire, wind, water, earth. Then came rarer elements—nature, blood, metal, lunar, fear, thunder.
But peace never lasts.
Enma, the Shadow God, fell into madness. His Shōin consumed him, and he unleashed devastation across the Overworld. Kojin was forced to cast him down into the Underworld, where he became the Shadow King.
Kojin himself ascended as the Sun King, withdrawing into his own dimension of peace. But even without the gods, wars erupted. Humanity, obsessed with its own power, even rejected Kojin. In despair, he erased almost everything, only to recreate the world decades later—a second chance for balance.
That was the world Renjiro lived in now.
He was lost in thought when he heard someone call his name.
"Yo, Renjiro!"
Kenji was waving from across the street, Ren standing beside him with his usual sharp-eyed expression.
"What's up, guys?" Renjiro asked.
"Not much," Kenji said with a grin. "Just signed up for something."
Ren smirked. "The Shōin Tournament."
Renjiro blinked. "…You're kidding. I signed up too."
The three of them exchanged looks. Fate had pulled them together.
But they all knew the truth. None of them were strong enough yet.
"Our Shōin isn't evolved enough," Renjiro admitted. "We'll get crushed like this."
"Then we train," Kenji said simply.
Renjiro nodded. "Tomorrow. Fire Shrine."
The next morning, the three of them stood before the shrine's massive gates. The air shimmered with heat, flames carved into the stone doors seeming to flicker like they were alive.
Inside, the air grew thick and heavy. At the altar, a figure of living fire rose before them, voice booming like a furnace.
"Welcome to the Fire Shrine. Here, your marks will be tested—and strengthened."
At that moment, the overwhelming Shinketsu inside the shrine surged through their bodies. Their Shōin marks pulsed and glowed with dazzling brilliance.
Renjiro's Metal Shōin shone silver, his arm gleaming like forged steel.
Kenji's Nature Shōin sprouted vines and roots that wrapped around his forearm.
Ren's Blood Shōin spread crimson curves across his skin, glowing darkly.
They had always known the nature of their Shōin. But never before had they felt this kind of raw, overflowing power. The shrine amplified their essence, showing them the true danger—and potential—of their marks.
Metal, Nature, and Blood. Three of the rarest Shōin in existence. The chance of being born with even one of them was less than half a percent.
Their abilities?
Shōin evolves in 3 stages:
Metal shōin stage 1:The user can create unbreakable weapons like sword,knives,daggers and even more.If he is defensive user,he can use a metal armor with reflective core.
Nature Shōin stage 1:The user can manifest spiky vines through his fingers that can absorb Shinketsu.It also gives him leaf-like wings that multiply speed by 2.
Blood Shōin stage 1:The user can shoot hard blood arrows that pierce even through metal.If used correctly,the user can manipulate the target's blood vessels.
They can evolve their Shōin by Shinketsu absorbing or by beating Shōin players in the tournament.
Renjiro remembered the first time they had awakened. It was four years ago, when the three of them wandered into the Light Shrine where the Sun King once lived.
Statues of Kojin lined the halls. At the center stood a glowing stone, radiating divine energy.
"Looks dangerous," Ren had muttered.
But Renjiro couldn't resist. He reached out and touched it.
Silver light exploded, searing marks across his arm. The stone's aura lashed out at Kenji and Ren as well, leaving them scarred with vines and blood-red sigils.
Normally, a Shōin awakened around the age of twenty. But that day, the shrine's Shinketsu forced their evolution early.
From then on, their fates had been bound together.
And now, four years later, they stood side by side once again.
One week remained.
One week until the tournament.
One week until Renjiro's battle for Akari