"Isn't that okay?"
(I knew you'd say that, but that was way too casual...)
It was late at night in his apartment. Mamoru was on the phone with his older brother, recounting the events of the day. That one-liner was the response he got.
"I wouldn't make a fuss about teaching someone how to manipulate cursed energy as a self-defense thing. Sure, those old guys obsessed with tradition might throw a fit, but I think it's fun, so whatever. Let 'em bark. It's not like the Health Department helps unregistered users anyway."
"...You're the only one who talks about sorcerers like they're stray cats."
Mamoru knew this side of his brother too well. He had a habit of "adopting" people he took an interest in—like collecting lost pets. Mamoru had been one of them once. Back when his own family wanted nothing to do with him, his brother simply said, "If you don't want him, I'll take him."
Still, Mamoru voiced his concern.
"Isn't it dangerous to stick your neck out without knowing how far you're willing to go?"
He wasn't entirely sure if teaching Kiryuin Fuuka was the right decision.
Yes, it made strategic sense—better to keep an eye on someone that reckless than leave them fumbling in the dark. If she got curious and started researching sorcery on her own, it could lead to disaster. At least this way, he could limit the damage.
But… that wasn't the only reason he agreed. Part of it was personal.
And that was what bothered him.
His brother's voice dropped its usual playful tone.
"Mamoru. You're overthinking this. Whether someone has power or not, if they're going to get caught up in something, they will. That girl wants to protect herself. I respect that."
"…Even so. I've never taught anyone before. And there's no real way to get practical experience inside school grounds."
"True, but if she's not aiming to be a full-fledged sorcerer, just teaching her cursed energy basics should be enough."
"And if she tries to go all-in?"
"Then we think about letting her use the Room."
Mamoru paused.
"…Is that really okay?"
Using the Room—his spatial formula that allowed teleportation to the outside world—was strictly off-record. Only Gojo Satoru knew it even existed.
"Only if you trust her. And let's be real—she probably already suspects you can contact the outside world. The higher-ups know you can teleport within certain ranges. They just don't know the exact mechanism."
Technically, it wasn't a classified secret that Mamoru could jump between towns. As long as it remained domestic, no one raised a fuss.
"What matters is that the Room stays hidden. Blindfold her while passing through it, and even if someone watches, they won't understand what they're seeing. An amateur won't detect the nature of that space."
"You're way too casual about this."
"Well, it's your spell formula, so I'll leave the call to you. But if you think she has talent, I'd like to meet her someday."
(Absolutely not.)
From what Mamoru had seen, Kiryuin was a free spirit—not unlike his brother. That wasn't a good thing.
Would they clash as similar personalities? Or spiral in chaos because they were too alike?
Either way, it wouldn't end well.
Then, Mamoru remembered something.
"Speaking of meetings… what about that orientation with the new students from the technical college? You said something about it before."
"Ah, right. Things got a little hectic, so I forgot."
"Trouble?"
"Don't worry about it. It's under control. Anyway, you've got exams coming up, right? And now you've got a student of your own to deal with, so let's schedule it after your tests."
"…That's fine, but—why do you sound so excited?"
Mamoru narrowed his eyes, sensing a tone shift.
"Nooo, nothing major. It's just that… a transfer student showed up recently. Pretty interesting kid. I thought you'd enjoy meeting him"
"… Eh? New transfer... are you picking another random kid again?"
"Yep. I'll let you see for yourself. No spoilers. I'll message you when the time comes."
With that, the call ended.
Mamoru stared at the dark screen, eyebrows slightly furrowed.
"…My brother's surprises are never fun for me."
There are two kinds of surprises: those made for others to enjoy… and those you do just to see the look on their faces.
His brother only ever did the latter.
Still, there was no point dwelling on it.
"I'll reply to Senpai tomorrow. I need to prep for now."
Tomorrow and the day after were weekends. He'd use the time to meet and talk with Kiryuin in person.
Once his preparations were done, Mamoru went to sleep.
◆◇◆
By the time morning arrived, Mamoru was back in his dorm, already typing on his device.
[Mamoru]: "Got approval from the higher-ups. Let's meet in person to discuss the details. Let me know a good time and place." Thumbs up emoji
He sent the message just after 7:30 a.m. Despite it being a school-free weekend, her reply came immediately.
[Kiryuin]: "Understood. I'm free anytime. You can even come to my room if you'd like."
Mamoru could feel her smirk through the screen.
But he wasn't the kind to get flustered over a teasing message.
He replied dryly.
[Mamoru]: "You brought it up. If you're joking, pick somewhere else. I don't like wasting time."
[Kiryuin]: "Sheesh, relax. Conversation is the oil that keeps life moving."
[Mamoru]: "…Hurry up."
[Kiryuin]: "Fine, fine. My room it is. Me walking into the second-year dorm would be a bit too conspicuous. Meet me in front of the convenience store at 10:00."
(Why am I so thrown off by that?)
[Mamoru]: "One or two people still stand out, but fair enough."
[Kiryuin]: "So, I take it you'll start teaching me today?"
[Mamoru]: "If that's what you want. I have time today and tomorrow."
[Kiryuin]: "Fufu. So I get your full attention."
[Mamoru]: "I'll supervise the basics, but you'll train alone. I don't have time to babysit."
[Kiryuin]: "Understood. See you soon."
He cut the conversation off there, not wanting to get dragged into her rhythm.
(Even after losing that much cursed energy yesterday, she's still eager...)
Mamoru had thought she'd cool down overnight. Maybe even reconsider.
But no. If anything, her resolve seemed stronger.
(Maybe the danger triggered her sense of survival...)
Perhaps tasting raw cursed power had shown her just how real the threat was. Maybe his attempt to scare her off had done the exact opposite.
(If she's still smiling after that, maybe that's a kind of talent in itself...)
Before he realized it, it was already past eight.
Mamoru finished packing up what he needed—study materials, cursed energy charts, a few sealing talismans—and left his room.
Of course, he avoided using his formula's storage function. He wasn't ready to reveal that much just yet.
"Alright. Time to go."
And with that, he stepped out, heading toward the meeting place.
***
Kiryuin was already at the meeting spot, dressed casually.
It looked like she'd been shopping—one hand held a shopping bag.
"Thanks for waiting."
"No problem. I just finished shopping. I even got here early. Pretty exemplary, right?"
"Thanks... I guess?" Mamoru replied dryly, his eyes dropping to the bag in her hand.
She had two shopping bags, each containing what appeared to be a lunch box and a drink.
"I figured we'd get hungry again later. Going out to eat would be a pain, so I bought lunch in advance. I'm not sure if it's to your taste, but one's for you."
"Oh, thanks. I'm not picky, so it's fine. By the way, how much was it?"
Originally, Mamoru had planned to grab a convenience store bento, so this saved him the trouble.
He took out his terminal to pay her back, but Kiryuin smiled and waved it off.
"You're the one doing the teaching, after all. I should probably cook and treat you properly, but… unfortunately, I can't cook."
"Why do you sound proud of that?"
Most girls might be embarrassed to admit they couldn't cook, but Kiryuin said it with total confidence.
"It's not like I'm bad at it. I just never thought it was necessary, so I didn't bother learning. It's pretty normal nowadays, too—no reason to feel inferior. What about you?"
"I'd say I'm decent."
After all, Mamoru had been living alone for a while.
He didn't care much about taste as long as it filled his stomach, but he couldn't serve his younger brother bad food when he visited. So he learned and naturally got better. Or his brother gonna died from sugar...
"Let's get going. We'll stand out just talking here."
"Makes sense. I wouldn't want to waste your precious time."
To Mamoru's surprise, Kiryuin nodded without argument. Or maybe she was just eager to get started with the lesson.
"Alright then. Let's go. This is what they call a 'home date,' right?"
"No."
With a swift retort to her teasing, the two headed toward the dorms.
Mamoru briefly wondered if a boy and a girl from different years walking together would draw attention, but luckily, it was exam season.
There weren't many students around. Aside from a few passersby, they reached the dorm without incident.
"Sorry for the intrusion."
"Welcome. Make yourself at home."
The room was just as Mamoru had imagined—clean and organized.
Unlike the pastel-heavy style common in girls' rooms, Kiryuin's had a more subdued tone. The furniture was chic and modern, giving the room a calm atmosphere.
"Let's start with a drink. Tea or coffee?"
"I'm good. I didn't come here to hang out. Let's get started."
With that, Mamoru created a barrier that enveloped the entire room.
"Oh, so this is a barrier?"
"Yeah. I doubt anyone next door would hear us, but this is just in case."
"I see. So if I got attacked right now, no one could help me."
"Do you have some sort of condition that kills you if you don't tease people?"
Her constant joking reminded Mamoru of his brother. That familiar pace wore him down.
"Fufu, sorry. When I see someone interesting, I can't help but poke at them. It's a habit. You'll get used to it."
"No, you should work on stopping it."
Kiryuin offered a cheeky smile, showing no remorse. Mamoru sighed and set down the bag he'd been carrying.
"Alright, enough. Senpai, for now, your first lesson is to destroy this."
He formed a hand seal, and a small barrier appeared at chest height in front of Kiryuin.
"I've been given permission to teach you about sorcery, but it's meaningless if you can't even refine cursed energy. Start by trying to break this with your fist—one infused with cursed energy."
At this stage, Kiryuin could see cursed spirits, but she still couldn't refine or manipulate cursed energy.
Without that, there was no way she could survive in this world. All he could do was give her the basics for now.
"Refining cursed energy, huh? How do you even do that?"
"Well," Mamoru began, "I mentioned before that curses are born from negative emotions. But technically, it's not the emotion itself that becomes energy. Everyone has cursed energy lying dormant inside. Emotions just trigger it to surface. Anger, hatred, jealousy, sadness—any strong feeling will do. When you feel it, you'll sense something well up from within. Focus on that sensation."
Mamoru wasn't sure if his explanation was good—this was his first time teaching sorcery—but he kept going.
Fortunately, Kiryuin seemed sharp enough to follow.
"Alright, I'll give it a try."
"Go ahead. Mind if I borrow a chair?"
"Sit wherever you want."
Mamoru sat near the desk and pulled a reference book from his bag.
(Well, I'm just winging it, but if she manages it today, that'll be impressive.)
As he cracked the book open, a heavy thud echoed through the room.
"Oh, right. That barrier's actually pretty tough, so until you can wrap cursed energy around your fist, it's going to hurt."
The barrier Mamoru created was designed to shatter the moment it detected cursed energy—but without it, it was as solid as iron.
Judging by the sound, she hadn't gone full force, but the barrier's glass-like look probably made her misjudge.
Another dull thud rang out. Kiryuin held her right hand with a wince, trying to stay calm despite the pain.
"Hah... I see. I'll be careful next time."
Hearing her slightly trembling voice as she tried to act composed, Mamoru felt an odd sense of relief inside.