Monday.
Hayashi Akira sat in the classroom, staring blankly at the blackboard.
Whatever the teacher was saying, not a word of it sank in.
His head was full of one thing:
How to summon the Tiger Sovereign.
"The catalyst is Itadori Yuji himself... but if I go to Sendai now, find him, and then what?"
A problem had occurred to him.
How could he be sure he would summon the Tiger Sovereign?
What if the summoning failed?
So he would need support. Incantations. Direction. Structure.
Akira decided to borrow from the logic of ritual magic, building a large-scale ritual in the field to improve the odds of success and reduce the cursed energy cost.
The summoning circles from Fate. Barrier techniques from onmyoji folklore. Magic circles from every anime he could remember...
He dragged out every element he could think of and tried to stitch them together into something usable. Real or fake, who cared? Jujutsu in this world was driven by belief anyway. If you believed it worked, that mattered.
First, the ritual circle.
Then, an incantation with directional intent.
Then, the summoning catalyst.
And finally, his own technique and the cursed energy it would consume.
The moment school ended, he rushed home and pulled out a notebook and pen.
Ori called from the living room, "Since when are you this motivated about homework?"
He started drawing.
First, a circle.
A circle meant repetition, protection, a barrier.
Then a triangle.
A triangle meant the three components - catalyst, cursed energy, technique.
"A binding vow."
Right.
"I can borrow against the future."
Akira suddenly remembered one of the most broken mechanics in this world:
Binding vows.
If you lived through it, great.
If you died, the debt died with you.
But would one week be enough?
For someone on the Tiger Sovereign's level, one month at minimum.
Little by little, the plan took shape.
Akira stared at the final page of the notebook and muttered slowly, "So... how do I get Itadori Yuji to stand in the center of the ritual?"
Students kept coming and going, but none of them had pink hair.
"Could he have skipped school today?" he asked.
"Saturday. Clubs are active," came the answer in his head.
Akira kept crouching there.
Another hour passed.
And then -
A pink-haired boy walked through the school gate, a sports bag slung over one shoulder, earbuds in, humming some song under his breath.
Itadori Yuji.
At this moment he was still just a middle school kid, athletic, overflowing with energy, completely unaware of what his life would become.
"That's him."
"The problem is how do I get him to stand inside the ritual? Do I just walk up and say, 'Hi, can I ask you to stand in this magic circle for a second?'"
Akira agonized over it.
He took a deep breath and followed.
Keeping about twenty yards back, he started thinking at full speed.
Go right up to him?
No.
Fake fainting and make him help?
Too forced.
Wait until he's asleep and move him over?
That was just a crime.
He was still turning it over when suddenly -
Yuji turned into an alley.
Then Akira froze.
A kitten?
Yuji looked up, spotted Akira, blinked once, then grinned.
Akira: "..."
He was silent for a second.
Then he crouched down and helped Yuji pull apart the box.
"You a student around here?" Yuji asked while prying it open.
"No," Akira said. "Just visiting Sendai."
"Oh! Then you got unlucky. The weather sucks today."
"It's not that bad."
Together they opened the box. A ginger kitten darted out, rubbed against Yuji's leg, and ran off.
Yuji stood up, dusted off his hands, and reached one hand out toward Akira.
The cursed energy inside Akira shuddered violently.
A chain of causality.
Wrapped all around Yuji were threads leading into both past and future.
Sukuna. Shibuya. The Culling Game. And also -
The Tiger Sovereign.
"Then we should get food fast," Yuji said warmly. "There's a bakery up ahead. It's really good. My treat?"
Akira looked at him.
Sunlight fell across Yuji's face, across that expression that had not yet been carved up by pain.
Akira did not know what to say.
"...Okay."
That evening.
Akira returned to Tokyo.
He lay on his bed, staring at the ceiling.
He kept remembering Yuji's face.
That boy who had smiled and offered to buy him bread.
"I'm going to save him. I'm going to break this fate," Akira said.
Friday. 2:00 a.m.
Akira slipped out of the apartment with a backpack over one shoulder.
"Using blood as a catalyst to reinforce the summoning..." he murmured. "It has to work."
After dozens of practice runs over three days, he could draw it with his eyes closed.
A circular ritual.
A triangle inside.
Dense layers of symbols packed across it.
Then the candles, placed according to direction.
Finally, he stood in the center of the ritual and pulled out a small plastic bag.
That afternoon, when they met, he had "accidentally" brushed something off Yuji's shoulder.
Akira had settled for the next best thing. Not the person himself - just hair.
He did not want to drag Yuji into the cesspool of the jujutsu world too early.
"The catalyst is here. Good enough." He drew in a deep breath.
"Let my blood be the guide."
He sliced open his fingertip, and blood dripped onto the ritual.
The circle lit with a pale glow.
"Let causality be the bridge."
The strand of Yuji's hair burned in his palm.
The light brightened.
"Let the future be the oath."
He remembered that old man with silver threaded through his hair.
Standing atop a mountain of corpses.
Those weary, merciful eyes.
"Binding vow!" he hissed through clenched teeth. "In exchange for losing the ability to summon for the next month, grant me success in this summoning!"
A formless pressure descended from the void.
Then, one second later -
The ritual circle erupted in blinding light.
Every candle went out.
The moonlight overhead seemed to be swallowed by something.
And then -
Countless branching rivers.
One of them surged toward him.
At the end of that river stood a man.
At the corner of his mouth was the exact same smile he had worn at seventeen.
Across the river of time, he looked at Akira.
"You made it."