“U-um…”

Shirayuki-sensei stood in front of the neatly sliced apples, clearly bewildered. After a moment, she found her words and spoke tentatively.

“T-to be honest, I didn’t expect you to pick this up so quickly, Itsuki-kun.”

“…Neither did I.”

It wasn’t just that Resonance was easier than expected; more so, I hadn’t anticipated that the same techniques from Elementis Recomposition would apply here.

I’m just as surprised as Shirayuki-sensei is.

“P-please wait for a moment!”

Shirayuki-sensei hurriedly flipped through her notebook, searching for the next step. She seemed to be looking for the next thing to teach based on the lesson plan.

She’s a pretty diligent teacher, I thought as I glanced outside the window.

Out on the training ground, a group of middle school-aged exorcists-in-training were doing warm-up exercises under my father’s watch. From the looks of it, they were starting with basic stretches.

“Itsuki-kun, let’s continue the lesson!”

I snapped back from my daydream at the sound of Sensei calling out to me.

Shirayuki-sensei had clearly found the right section in her notes, her face now bright with enthusiasm.

Such an easy-to-read teacher, I thought with a smile as I nodded.

“Let’s do it!”

“Actually, the plan was to spend the entire day building up the basics of Resonance. But since you’ve already got it, we can move on to the next step!”

With that, Sensei pulled out a baseball and another apple.

Wait, what? These objects are completely different in shape and size.

“When you tried Resonance earlier, you probably noticed that similar objects resonate much more easily. But how about these?”

Shirayuki-sensei placed the two items on my desk.

“The baseball is a sphere, right? B-but doesn’t the apple also look like a sphere?”

“…Yeah.”

I nodded, though somewhat doubtful.

I mean, if you had to categorize the shape of an apple, “sphere” was the closest option. No one would call an apple a cube, after all.

Still, there was something that bothered me.

“But, Sensei, even if the shapes are similar, aren’t they also pretty different?”

“That’s a good question. Now, Itsuki-kun, have you ever heard of Katashiro?”

I was about to say that the baseball and apple didn’t seem all that similar when Sensei asked her question, as if anticipating my thoughts.

“Katashiro…?”

“Yes, Katashiro.”

Wait, Katashiro? What does that mean? How is it written?

The word alone didn’t give me any clear idea.

“Like this.”

Shirayuki-sensei pulled out a clear file with a piece of paper inside. But this wasn’t just an ordinary sheet of paper—it was cut into the shape of a person. It immediately reminded me of something from a manga I read in my past life. It looked like the type of paper an onmyouji might use.

Ah, so this is what’s called Katashiro?

But… should you really be putting that in a clear file?

As I pondered these trivial things, Sensei continued.

“This is something exorcists used about a thousand years ago, called Katashiro. Doesn’t it look somewhat like a person?”

“It does.” .net

“Exorcists used this person-shaped paper to resonate with demons and either exorcise them or even defeat political enemies.”

Wait… political enemies?

“This is just paper, and while it vaguely looks like a person, the shape, material, and size are all totally different, right? Yet, it was still able to resonate with actual people. S-so if that was possible, doesn’t it seem more feasible that you could resonate something like an apple and a baseball?”

I shifted my gaze from the Katashiro in the clear file to the apple and baseball on my desk.

Comparatively, the apple and baseball were much more alike than a piece of paper and a human. It definitely seemed easier now.

Though I couldn’t shake off what Sensei had said earlier about “defeating political enemies.” Still, now wasn’t the time to get distracted. I had to focus on the lesson.

“Alright, I’ll give it a try…!”

“It’s quite difficult!”

I conjured Silveit in both hands, wrapping one thread around the apple and the other around the baseball. But the moment I tried to make them resonate, I failed. The sensation was off immediately; the connection wavered the instant the threads touched.

I tried again, but the second attempt was also a failure.

…This is harder than I thought.

Taking a deep breath, I prepared to try again.

“The apple and the model earlier were very similar, you see. Their shapes, appearances, and sizes were almost identical. The only difference was the material. T-that’s why it was the basic foundation of Resonance.”

As I focused on adjusting the magic flow through the Silveit threads, Sensei spoke softly.

“But when it comes to actual fieldwork, you won’t always have the luxury of using models or life-sized dummies of the demons. That’s why you need to learn to resonate objects that are just slightly similar. Otherwise, Resonance is useless in real combat.”

Nodding along with her words, I kept working through the failures.

She had a point.

In the middle of a battle with a demon, you wouldn’t have time to pull out a model of the creature. And even if you did, in most cases it would be faster just to use regular magic attacks.

…No wonder Resonance is unpopular.

As I listened to the sounds of sparring from the training grounds outside, I couldn’t help but think about how much more beneficial it would be for most exorcists-in-training to attend my father’s or Renji-san’s lessons.

While these thoughts swirled, Shirayuki-sensei leaned forward slightly and spoke with more enthusiasm.

“A-as I mentioned, the earlier practice was the training phase of Resonance! Now, we’re moving on to the real challenge! You can do this, Itsuki-kun!”

“I-I’ll do my best…!”

Motivated by Sensei’s encouraging words, I focused on adjusting the magic flow again.

This really was difficult. Rather than trying to finely control the magic, it seemed easier to apply a more general approach, like aiming for an overall balance.

As I kept experimenting and refining my approach, I started to feel some progress.

After three full hours of work, I finally succeeded in resonating the apple and the baseball.

Source: Webnovel.com, updated by NovelKeep