Shoichi Kano pretended he knew nothing, sucking on the lemon candy in his mouth as he studied the spatial vector problem in front of him.
"Well, well!" Mr. Tanaka erupted in anger. "Yamakawa, sneaking candy in my class? You can stand for the rest of the lesson!"
"Kano, laugh again and you can stand with him!"
Once he had finally endured the math lesson, Shoichi Kano hurriedly pulled out the notebooks Lord Kenjaku had sent someone to deliver. There were seven hefty volumes, each around two hundred pages long, all filled with knowledge of Barrier Techniques compiled by Kenjaku.
When Shoichi Kano opened one of the notebooks to its first page and saw the elegantly written classical Japanese, he knew that old bastard must have put considerable effort into compiling all this.
You think I can't learn it? A fire burned inside Shoichi Kano, too. Then I'll damn well show you!
That was why he had taken the notebooks straight to school after receiving the package, before even the Slit-Mouthed Woman had a chance to look at them.
But Kenjaku's very first sentence left his head swimming: "The essence of a barrier is an expression of a Binding Vow. By restricting the conditions of entry and exit, one constructs a 'barrier' conforming to a particular paradigm."
How did barriers have anything to do with Binding Vows? And what the hell was a particular paradigm?
Shoichi Kano felt as though he had returned to his university days in his previous life and was leafing through a college textbook.
So he flipped back to the table of contents in the volume he was holding.
Well, then. The first three chapters were "The definition of Barrier Techniques," "The origins and developmental history of Barrier Techniques," and "Common forms of Barrier Techniques."
Seriously, Kenjaku's talents were wasted on anything other than writing university textbooks. If she wanted, the University of Tokyo could probably establish a Jujutsu department on the spot and appoint her as a doctoral adviser specializing in Barrier Techniques.
He patiently read page after page, marking specific questions in pencil.
So when Ms. Kanroji walked into the classroom to teach Japanese, she assumed Shoichi Kano was diligently reviewing the classical texts assigned for the exam. She nodded in satisfaction before moving on to check on the next student.
After Kano finally managed to skim through the first volume, he regained a little confidence. Barrier Techniques aren't that complicated! I understand them completely! All you have to do is draw a circle, agree on the conditions of a Binding Vow with the heavens, specify who can enter and who can't, what you want to imprison, and so on. That's a basic barrier!
Brimming with enthusiasm, he opened the second volume: "Applications of equation-based thinking in modern Barrier Techniques."
Chapter one: "How to use electromagnetic induction formulas to quantitatively adjust a Barrier Technique's interference with lightning cursed energy of specific frequencies."
Shoichi Kano thought he had misread it, so he turned to chapter two: "What complex solutions to parametric equations represent in Barrier Techniques."
Chapter three: "How to use specific equations lacking stable analytical solutions to construct disposable barriers that cause internal destruction."
Shoichi Kano's head was full of question marks. He could scratch his scalp raw and still never understand how one book could be discussing Japanese onmyōdō with Abe no Seimei and examining crude Barrier Techniques rooted in local folk traditions, only for the next book's difficulty to shoot straight through the roof.
Still refusing to give up, Kano set that volume beside him and looked at the third: "Topology and planar barriers."
Volume four: "Spatial vectors and boundaryless barriers."
This one looks understandable! I know spatial vectors! Aren't boundaryless barriers just Open Domains? If Kenjaku can pull off an Open Domain like "Domain Expansion: Womb Profusion," then I, Shoichi Kano, am no worse!
And so he eagerly opened the fourth volume.
Then the densely packed formulas inside blew his mind. What did it mean that converting between Open Domains and closed domains required trigonometric functions over the complex numbers and spatial identity transformations? How could phrases like "clearly, we obtain," "it is easily proven," and "observe that" start popping up before he even understood the first step?! Were their powers of observation really that fucking incredible?
After roughly leafing through the volume, he realized he was on the verge of forgetting even the basic vector knowledge he had learned in high school. This shit was way too hard.
So he quietly put those books away and obediently returned to his own textbook.
The Slit-Mouthed Woman came to pick him up after school as usual, but when they reached home, they found another delivery box outside the door.
Neither a sender nor a recipient was listed on the box, and Shoichi Kano kept feeling an ominous aura emanating from within.
"Someone who can leave a box at our door without triggering my barrier..." The Slit-Mouthed Woman stepped forward and picked it up. "Who else could it be but her?"
Once they were inside, the Slit-Mouthed Woman eagerly opened the package and found three things:
The first was an oblong box about the size of a glasses case, the second an envelope, and the third an elongated object about as long as an ordinary human finger, wrapped in strips of paper inscribed with incantations.
The Slit-Mouthed Woman did not let the power within easy reach go to her head. Instead, she chose to open the envelope first.
The letter's contents were straightforward. In short, Kenjaku had arranged a false identity for the Slit-Mouthed Woman that would get her through customs in various countries. Meanwhile, the "glasses case" contained a special Cursed Tool that would allow ordinary people with no talent for Jujutsu to see her.
The Cursed Tool was simple to use, too. All she had to do was hold it and inject cursed energy to activate it, and it would merge into the Slit-Mouthed Woman's body. Afterward, she could choose whether to make herself visible to ordinary people, including standard cameras.
Kenjaku also pointed out that the Cursed Tool had a tracking function. This was a necessary form of surveillance to prevent them from slacking off during their business trip.
Next came the matter of Sukuna's Finger. Kenjaku wrote that the Slit-Mouthed Woman needed to swallow the paper inscribed with incantations along with the finger. That would allow her to safely absorb the finger's cursed energy without disturbing Sukuna's soul inside it.
The other sheet concerned their trip to China. Kenjaku had confirmed that the Cursed Tool was last seen around Huimin District in Hohhot, Inner Mongolia, but they would have to investigate locally to determine its precise whereabouts.
Kenjaku also suggested setting off in July, because Tengen's barrier would develop problems then due to the failed assimilation. At that point, the Slit-Mouthed Woman, as a curse born in Japan, would be able to leave the country safely.
A printed photograph was attached at the bottom of the last sheet. It showed a Western-style wall clock with yellow talismans stuck to it. Kenjaku said this was the Cursed Tool she wanted recovered. Its function involved time, and it would prove useful in her future plans.
After reading the letter, the Slit-Mouthed Woman tossed the two sheets to Kano, then continued opening the "glasses case," looking exactly like someone unpacking an online shopping order.
Inside the glasses case was a pair of eyeballs, one pure black and one pure white. They looked somewhat like human eyes, but not quite.
The Slit-Mouthed Woman barely hesitated. She simply examined the eyeballs, confirmed they were safe, and decisively slapped them into her body.
Next came Sukuna's Finger.
"Nom!" She opened her mouth as wide as she could without snapping the stitches at its corners and stuffed the oblong bundle of talisman paper inside. Her throat worked a few times as she forcibly swallowed it.
She even drank some water from her own cup afterward, intending to wash it down.
The eruption of cursed energy always came without warning. Shoichi Kano had thought she had already finished absorbing the finger and everything was fine. He was just about to get up and head to the bathroom when a cold, sinister blast of air suddenly erupted behind him.
Bang! The blast slammed him into the wall, leaving stars dancing before his eyes.
The Slit-Mouthed Woman soon felt the vast amount of unfamiliar cursed energy pouring into her body. Guided by her existing cursed energy, it was rapidly assimilated and filled her body, making her feel a clear increase in her total reserves.
"Ooooooh!" What was lethally poisonous to ordinary people, however, brought nothing short of intense pleasure to Cursed Spirits. "Ooooh, ho, ho... haaah... haaah... mmm..."
"Haaah... it's... it's coming again!"
Shoichi Kano had only just recovered from the dizziness of hitting the wall when he heard those suggestive noises behind him. He immediately felt a massive headache coming on!
Before you continue