Curses.
Negative emotions such as fear, grief, anger, hatred, and envy are the foundation of cursed energy.
These emotions exist to some degree within most humans, and as a result, the vast majority of human beings possess cursed energy.
If this amount exceeds a certain threshold, it grants the individual the ability to see cursed spirits. These individuals are known as jujutsu sorcerers, and they are exceedingly rare among the human race.
Cursed energy leaks from the human body, accumulates, and ferments over time until a cursed spirit manifests.
This phenomenon occurs only in non-sorcerers, as sorcerers are trained to control and channel their cursed energy into jujutsu.
For thousands of years, jujutsu sorcerers trained and researched cursed energy, inventing new theories as they delved deeper into the world of curses, establishing their own factions and schools.
Jujutsu High School, Tokyo.
One of the two schools in Japan where the strongest sorcerer of the current era, Gojo Satoru, teaches.
***
In the suburbs of Tokyo, a traditional-style building stood tall atop a mountain. The board of Jujutsu High hung high, imposing as the school held itself with pride.
The sun was at its peak, sunlight gracing Jujutsu High with its presence.
"So let me get this straight. Fourth grade, third grade, second grade, first grade, and finally special grade."
Holding an old book in his hands, the pink-haired boy repeated the information as he looked at the other two present inside the classroom.
"What's the difference between them?"
"You don't even know that?" Nobara Kugisaki said, looking at him in disbelief. "Why are you even in Jujutsu High?"
"Sigh…" With his elbows resting on the bench and his chin supported by his hands, Megumi sighed. "There are a lot of differences."
"First of all, combat capability. A fourth-grade curse can be handled by almost anyone. In non-jujutsu terms—"
"A wooden bat would be enough to deal with a fourth-grade curse. But for a third-grade curse, you'd need a pistol."
"Yeah! But from second grade onward, the real difficulty starts!" Nobara added. "A point-blank shotgun blast or even a sniper rifle—that's how much power you'd need to deal with a second-grade curse."
"For a first-grade curse…" Megumi continued. "A tank wouldn't be enough. And as for special grades—missiles and bombs would be required, at the very least."
"They're that dangerous?" Itadori asked curiously as he placed the book down. "Man, being a jujutsu sorcerer sure is crazy."
The three sat in the dim classroom, each lost in their own thoughts, waiting for the one who had summoned them.
"Any idea where Sensei is?" Itadori asked. "He told us to wait here, but he's late."
"I'm pretty sure he forgot he even summoned us," Nobara said, folding her arms in frustration.
"Maybe he went to buy some cakes…" Megumi muttered.
"That does sound like something he'd do," Nobara replied.
Click.
The classroom door suddenly slid open as the familiar white-haired man entered animatedly.
"Hello, my dear students!" Gojo spun dramatically, striking a pose as he looked at the unresponsive trio. "Did you miss me?"
"No," Megumi replied immediately, his dry tone making Gojo clutch his chest as if struck by an arrow.
"Not at all," Nobara added, delivering the second blow.
"I missed you, Sensei!" Yuji said brightly.
"Oh, Yuji! You are my favourite student!" Gojo cried theatrically as he appeared right in front of him.
"So why did you call us here?" Nobara asked, cutting straight to the point.
"Oh right!" Gojo exclaimed, clapping his hands together as he walked toward the podium. "Everyone! Today, we're getting a new addition to our little class."
"What?" Nobara reacted instantly.
"I'll now be introducing," Gojo continued with exaggerated gestures, "the fourth student of Jujutsu High—first year!"
All three students straightened in their seats.
"He's already here?" Megumi muttered.
"Everyone," Gojo said dramatically, "give a round of applause for the new addition to the class!"
Clap. Clap.
Yuji clapped enthusiastically as Gojo gestured toward the door.
"Amakawa Haruto!"
The door slid open as Yuji's clapping grew louder with anticipation.
Clap… clap… clap…
The clapping slowed, then stopped.
Yuji blinked, staring at the empty corridor.
"Uh, Sensei? There's no one there."
Gojo smiled sheepishly. "Ah, sorry. Wrong gate. Let's try that again."
"Everyone, welcome—Haruto Amakawa!"
The door slid open once more.
A teenage boy dressed in black stood silently behind it.
"Is this—" Yuji began, but his words froze in his throat.
A terrible sense of dread flooded the classroom.
The air grew heavy. Instincts screamed danger as dense, abysmally vast cursed energy flooded the space.
Step.
The boy took a single step inside.
The pressure intensified.
"Divine Dogs."
Two shikigami materialized instantly, black and white, growling toward the newcomer as Megumi leapt back, hands forming the familiar sign.
Nobara pulled out her hammer and nails.
Yuji shifted into a fighting stance, gripping the Slaughter Demon.
"Haruto!" Gojo announced cheerfully, placing his hands on Megumi's shoulders. "Welcome to Jujutsu High. These are your classmates for the next three years."
Grinning widely, Gojo gestured toward the stunned trio.
"And everyone—meet Haruto Amakawa."
"The new addition."