Sunday.
"Well, this room's nothing special."
Huana slipped off her shoes and tucked them neatly into the shoe rack, then looked around Matyos's room.
An achromatic space, largely unadorned. Not a single decoration on the walls, and the clothes hanging on the rack were as tidy as their owner's personality.
On the desk, an open grimoire, a writing notebook, and an inkwell were arranged in orderly fashion.
Huana sniffed as if she disapproved of the sight, but soon strode over to the bed and sat down.
Then, without the slightest hesitation, she flopped backward and pulled the blanket over herself.
"Hmmmm…."
The sound of her breathing in the blanket deeply.
"…What are you doing?"
"Ahem! Nothing."
Huana snapped upright.
A moment later, there was a knock.
Matyos went and opened the door.
It was Ofilienne.
Incongruously, she was cradling a large stuffed bear in her arms.
"So this is Mati's room."
Ofilienne's eyes gleamed with a subtle light as she looked around.
Her gaze moved slowly, like someone drawing out old memories one by one.
The study venue had ultimately been decided as Matyos's room.
Several locations had been proposed, but this one won out as the most comfortable.
Here, they would compete to see who could teach Matyos better.
Once all three of them stepped inside, the room — which had seemed quite spacious — grew oddly cramped.
"Mati."
Ofilienne approached and spoke.
"A gift."
She pressed the large stuffed bear firmly into Matyos's arms.
"…A teddy bear?"
Matyos, now half-forcibly hugging a bear nearly his own size, looked up at her with a sulky expression.
Ofilienne covered her mouth and giggled.
"You used to sleep hugging a teddy bear whenever I wasn't around. Don't you remember?"
His face flushed hot in an instant.
It was an embarrassing memory.
Matyos answered in a smaller voice.
"…That was then."
At the smaller voice, Ofilienne's smile deepened at the corners of her eyes.
"And who was it that cried and made a fuss asking where his sister was? Hmm."
Ofilienne cut herself off, then glanced sidelong at Huana with a quiet smile. Huana's face had gone stiff.
"Is it rude to say such things in front of company?"
"I'm not company…!"
Huana shot back reflexively.
"Anyway, it's a gift. I brought it from my room — it was still there. This is the one you used to hug every day."
He had no idea why she'd kept it all this time, but Matyos set the stuffed bear down on the bed.
"I'll accept it gratefully."
He still didn't love being treated like a baby, but a gift was a gift.
…And it was kind of cute, he supposed.
"By the way, Huana — didn't you bring anything? You're coming to someone else's room, after all…?"
"Th-that's…!"
Huana stumbled over her words for a moment, then lifted her chin.
"I came, didn't I? A princess like me showing up is gift enough. My presence itself is the present!"
Ofilienne seemed briefly at a loss for words at Huana's bold declaration, then nodded with a gentle smile.
"Right, of course."
"…So, Sister — did you actually come prepared?"
"Naturally."
She gestured and opened a pocket dimension.
A single notebook appeared.
"Pfft, what's that? Just one?"
Huana burst out laughing without even trying to hide it.
When magic was organized into formulas, it became extraordinarily vast.
Even recording a single basic spell in full required a volume the size of an encyclopedia.
Yet the notebook Ofilienne had produced was thin.
It wasn't thick enough to hold even one spell, let alone three.
"Allow me to show you what I've prepared."
Already wearing the smile of victory, Huana opened her pocket dimension with a confident flourish.
A cascade of thick books tumbled out.
"If you're going to study, this much is the bare minimum, isn't it?"
"Well, we'll see about that."
Ofilienne smiled pleasantly and gave a small shrug.
"So, who goes first?"
"I'll go first."
"All right, then."
Huana boldly pulled Matyos by the arm and sat him down beside her.
She turned her head to face him.
"You're ready, right?"
"Yeah."
"I've never taught anyone before."
"?"
Matyos didn't understand for a moment. Wasn't that… a bad thing?
"So you should feel honored. A private lesson from a princess! Get tutored by me and you'll be casting magic in no time."
"Got it."
"Phew, then let's begin."
With a resolute heart, Huana opened the first page of the thick grimoire.
'With this, I'll wipe that smug look right off Sister's face.'
Huana was brimming with confidence.
The once-in-a-generation genius, the Phoenix of Hispanya, the Eternal Beacon.
All of them were words used to describe her.
When it came to magic, she was confident she was the most gifted among her peers. Fire magic in particular was her specialty.
But it wasn't only fire magic she excelled at.
She possessed overwhelming talent in other fields of magic as well.
'There's no way I can't teach this.'
Obviously.
This was magic she had fully mastered herself. She'd used it hundreds of times. Teaching it to someone else as-is should have been simple.
Glance.
She looked at Ofilienne.
She was lounging on Matyos's bed with an unhurried expression, chin resting on her hand.
As if the outcome had already been decided.
…That insufferable expression won't last long.
"All right, Mati. Look at this."
Huana pointed to the formula for Fireball with her pencil.
"You have a rough idea of the basic equations for fire magic, right?"
"Yeah."
"Professor Kennedy added amplification and dispersion on top of that. You followed up to there."
"Yeah."
"Add those in and you're done."
"Hm?"
Matyos looked up sharply from the grimoire. Done how, exactly?
He looked at Huana with eyes that asked for more explanation, but she turned to the next page.
"Easy, right? Let's move straight on."
"Wait, wait."
"What?"
"…I don't understand it yet."
"Huh."
Huana blinked. She pulled the previous page back.
"I'll explain again. You just add amplification and dispersion to the basic Fireball."
"How do you do that? If you're assigning two properties, you have to modify the base formula."
"You just do it with feel."
"…With feel?"
Matyos was baffled — those words had no business being near a systematic set of equations.
"Yeah, with feel. If you just cast the basic spell it feels empty, right? So you fill it in with something more substantial — that's the amplification and dispersion."
"I don't get it…."
"O-oh? It's nothing, really. I'll explain it again right away."
After that, Huana tried to explain the magic to Matyos again and again —
"Around this point in the calculation, you'll vaguely notice something that's slightly off. You just insert the amplification there. Hm? How do you insert it? Um… you just… kind of?"
"This isn't working. Let me explain Barrier first. Barrier is easier. The professor didn't really touch this one — if you just try it, you'll get a feel for it. Then you go with that feel… do you understand…?"
"…That's not working either? Th-then I'll teach you Strength. Strength is, um… I do this one by instinct too… w-well, for now. You apply magic to your body. Then there's this — pow! — kind of sensation, and then you spread that sensation all over your body like this…!!"
— Matyos did not understand.
Feeling sorry for Huana as she grew increasingly desperate in her explanations, he nodded along as if he'd gotten it, but Huana herself was coming to feel just how dismal her teaching was.
"Th-this isn't right…."
Huana was growing more and more flustered.
She flipped through the pages with increasingly moist eyes, but no answer came.
Nothing — nothing at all — could help her teach Matyos.
She had learned magic by instinct.
She cast by instinct, and understood by instinct.
And so she couldn't explain it systematically, the way one would explain a mathematical formula.
"Is it my turn now?"
Ofilienne, who had been watching the whole thing, rose slowly to her feet.
Huana stepped aside like a defeated soldier.
Ofilienne did not sit across from Matyos.
She came to his side and pulled a chair close.
"Don't worry. I won't make it as complicated as Huana did. Just focus and listen to what I say."
Thud — she set the notebook on the desk.
Unlike Huana's thick stack of grimoires, Ofilienne's notebook was thin.
But every page was densely filled with diagrams and annotations.
"Amplification and dispersion are commonly used structures. However, the professor put considerable emphasis on the dispersion side. There's nothing particularly difficult about it. First."
Ofilienne divided the flow of the base formula with arrows.
"This is fire generation. This is form maintenance. Everything up to here is the foundation."
Then.
"Amplification only operates at this stage. The reason is simple."
She covered one of the arrows with her finger.
"If you apply amplification after the form is fixed, the mana runs wild. So it always goes immediately after formation."
Matyos's eyes widened.
"…Ah."
"You understand now, don't you?"
"Yeah. Why the professor placed it at that position."
Ofilienne nodded.
"Dispersion is the same principle. Dispersion isn't directly tied to attack power."
"Then why use it?"
"Hit rate."
"Hit rate…."
"The most important thing in combat is landing the hit."
She said it simply.
"Fireball was used in warfare. It's more efficient to strike many targets with lower power than to kill fewer with greater power. So a little power was sacrificed in favor of dispersion."
It was completely different from Huana's explanation.
Everything Matyos had failed to understand until moments ago became cleanly clear.
"Mati, can you say it back to me?"
Matyos thought for a moment, then spoke.
"Apply amplification immediately after formation, then layer dispersion at the release stage."
"Exactly."
Ofilienne's eyes curved softly.
"See. You can do it."
The words were praise, but they carried no excitement.
She sounded like someone who had known all along that he would get it.
"The principle behind Barrier is similar."
She turned the page.
"I'd like to explain more… shall we continue? Huana."
"…."
Ofilienne glanced back at Huana.
She was slumped over like a rain-soaked sparrow.
"…It's fine. I lost."
With that, Huana gathered up all her stacked grimoires and left the room.
Matyos saw her off.
"Well, see you next time."
"…Yeah. See you."
She disappeared from Matyos's sight, still deep in shock.
"Then."
At that moment, Ofilienne wrapped her arms around Matyos's neck from behind. A chill ran through him for no reason he could name.
She brought her lips softly to his ear and whispered.
"I'm counting on you from here on, all right? Mati."