Chapter 3.2

It’s cold.

It’s dark.

But moreover…

…Hah—

It’s beautiful.

I squeeze my hands.

Hearing the faint rustling of leaves.

Looking up at the sky.

The stars peering through dispersed clouds.

I actually missed this…

It’s been so long since the sky opened up.

…

Winter’s coming around; they’ll be obscured again.

At least—I got to see them today.

…A strong wind comes again.

I pull up my scarf, covering half of my face.

Little by little, the trees grow devoid of leaves.

Then, falling beside me.

A dry maple leaf.

…

The sky slowly… begins to light up.

Stars begin to blend in, but—

The birds have woken up.

I look around, spotting no signs of them.

Yet I hear it—their gentle chirps.

…Mom would love this.

I breathe in once more, and slowly let it out.

I raise my hand, seeing my watch…

It’s six already.

Perhaps I should leave.

I pick up my bag, hanging the strap over my shoulder and…

I take the leaf.

Hundreds of them scattered on the grassy slope but this one…

I hold it by the stem, hmm—

Taking my phone, I open the camera.

But, it’s a bit too dark…

Still—I take a grainy photo of the leaf.

…I’ll just bring this with me, I guess.

I stuff my phone in my pocket, and leave the park.

The leaves crunch beneath my feet, until I eventually return to the streets.

I pass through narrow streets and watch as I pass by my home.

I should do this more often.

A bit of a hassle to wake up so early but… there’s barely anyone out by this hour.

Hah—I watched my breath turn to fog, and there the sun began to peek.

I look at the leaf I held, twirling it around.

Why did I even…

Maybe I’ll just give it to him.

Eventually, I saw the open field.

There I looked at myself in the convex mirror.

…There’s a leaf in—

I pluck it out of my hair, a disheveled leaf.

It’s good that I looked…

It’s quite small.

The stem is fine but… the rest is completely torn apart.

I’ll give this one to him.

…I continued my walk, the stars no longer visible as the school gates came into view.

It’s open, okay.

The courtyard… wasn’t as dense as before.

It seems the officers have been tending to it well.

Or perhaps the trees are just… losing too many leaves.

“...Good—morning…?”

I turn around, seeing… umm—

Ah.

“Hoshino-san?” I look at her smiling at me. “Good morning… you’re here early.”

“Mhm, I woke up too early, you see…” She lets out a slight laugh.

Right, I have it with me.

“Can you hold these for a moment…?” I hand her both the leaves.

“...What’s this for?”

I search through my bag and take out my… lip balm.

“Here,” I hand it to her with an open palm.

She returns the leaves and looks at it.

“Mentholatum…? Where’d you buy it?”

“...My mom gave it to me, I don’t know where she got it from,” I scratch my cheek.

“I see… it suits you well,” she smiles.

“Please don’t flatter me…”

Hoshino-san returns the lip balm, and looks at the leaves in my hand.

“Picking up leaves?” I hear her giggle.

“Ah—it just happened…”

“That’s cute,” she smiles at me again.

“...Want one?”

“May I?”

I hand her the bigger leaf.

“I’ll show this to Mugi and make her jealous,” she says and begins walking forward. “Bye bye!”

I raised my hand and waved as she grew farther away.

Now I’m left with… the smaller leaf.

It’s kind of cute actually.

I wonder if he’ll take it.

…I glance behind me and see some students already arriving.

They’re rather early.

Maybe clubs…?

I look around one final time, seeing the sky completely lit up by the morning sun.

Then… with nothing else to see, I turn to the school building.

…I wear my slippers and… walk through the hallway.

Stopping right at our classroom.

No one’s here yet.

I look around, before… stepping through.

It’s a bit cold.

I leave the door open, and head straight for my seat.

Hanging my bag under my desk and just…

Remain seated.

I hold the leaf again, before leaving it on my desk.

I stand, unlocking the window and letting all the cold air seep in.

Hm… I take in everything.

That’s so much better.

The front door slid open, and Watanabe-san with some of our classmates arrived.

Hah… I lean forward—resting my chin on the desk as I just held the leaf again and stared at it.

Maybe I should’ve stayed at the park for longer.

…Come to think of it—I didn’t tell Mugi I was absent.

Maybe Hayashi told her…?

Hmm.

Probably not.

I turn to look outside again, the sky still there.

Hopefully it stays that way… we’re already this deep into autumn.

I do hope we get white Christmas.

It’s kind of rare in this part of Japan…

I sit properly, leaving the leaf on my desk once more.

…I’m bored.

I can’t really sleep again, can I…?

I scratch my head, looking around to see barely any people.

I… take the leaf and put it under my desk, and finally.

…Bury my face in my arms.

…

…

“...on the phone?”

“No, she sent a message one time—that’s it.”

“Ooooh? Can I see?”

…I lift my head up, looking to my right to see… Hayashi and Mugi.

Hayashi fiddled with his phone, before showing it to her.

“You sure that’s her…?”

“I mean, it sounds like her.”

She laughs before—

“Oh,” she finally noticed me. “Mizuki, how have you been?” Mugi hurries towards me and just pats my head.

“I’m fine… why are you here…?”

“Well obviously I missed you,” she says. “You sent him a text last week?”

“...Yeah, I forgot to return his console.”

Then, she laughs again.

“Wait—wait—look, here’s how my friends usually text.”

She takes her phone, pressing buttons rapidly before, facing it towards me.

…

Why so many…?

“It’s not like I have unlimited load,” I mentioned. “And I didn’t really have anything else to say.”

“You’re just like my dad,” Mugi holds back a laugh as she returns to her phone.

Ah, right.

I lean down, reaching for my bag and taking the console out.

“Here… Hayashi, I’m sorry you didn’t get to use it.”

“It’s no worries,” he shakes his head, taking it from my hand.

“...Mugi, don’t you have anything else to do?” I ask since… she never just stands around.

“No? All my duties are for later.”

“I see.”

“Ah—you’re so unfair actually, Hoshino showed me something earlier.”

“...The leaf?”

“What’s up with that?”

“I asked if she wanted one.”

“She just kept flaunting it to me in class…” Mugi scratches her head. “Why’d you have a leaf anyway?”

“I just picked it up from the park.”

“...Seto park? You were there?”

“Mhm, I just needed the fresh air.”

She looks at me, then smiles.

“Well—if you find a better leaf, give it to me next time.” I nod and she looks outside to see people… waiting for someone? “Ah, that’s me—I’ll be off then,” she lightly waves her hand, runs past Hayashi and to the crowd waiting for her outside.

“How lively,” Hayashi comments.

“She is…”

…

Should I have given Mugi this leaf?

But she wanted a better one…

I suppose next time.

“...Hayashi.”

He turns to me.

I show him the small leaf.

“Take it.”

He looks at it for a moment, then me—before reaching for it.

I watch as he stares at it, then looks at me.

“Why not give this one to the pres?”

“...Well, she said she wanted a better leaf.”

“Hm… thanks,” he looks at it again, then begins searching for something. “Is it fine if… I keep this in a book…? To make sure it isn't—”

“Ah—yeah, it’s yours anyway.”

He continues to search under his desk until eventually… he just leans back against his chair.

“Don’t have a book?”

“Yeah, I’ll just do it at home later,” he says while twirling the leaf around before hiding it under his desk.

…I’ve given it to him.

Now what?

I let out a sigh, leaning back and looking outside.

Hmm… so many clouds, but it’s still so bright.

At least it’s cold enough that I can actually wear my scarf.

The doors swung open, Aoi-sensei arriving on time as usual.

I look forward, watching her stare at her desk for a moment—skimming through a paper she brought.

“Just a reminder, we’ll be having the second semester’s midterm examination by November 15th… and 18th, be thankful—you have a weekend to review between examinations.”

We all nod.

Her eyes look down for a moment, before turning to us.

“I suppose we can get started immediately,” with an audible inhale—followed by a breathy exhale. “Wave motions, we discussed this in our previous lesson and will be fundamental to our following lessons… what does a wave do again…? Taiki?”

…All eyes turn to Taiki-kun, who stands with no words.

“Sit down, anyone?”

A hand is raised at the front, “It’s the transfer of energy… from one place to another.”

“Mhm, and we learned that waves can be classified in different ways. A familiar example of this is… sound and light.”

Sound.

Light.

Written on the board.

“...Anyone?”

“Light travels faster,” I hear beside me, Hayashi.

“Correct. In the case of a thunderstorm, we see lightning before we hear thunder. But I would like to discuss the more fundamental difference between the two.

She turns to the board, writing “Mechanical” for sound, and “Electromagnetic” for light.

“Having discussed these classifications previously, a mechanical wave requires a medium to pass through. This consists of air, water, anything with matter whose particles can transmit vibrations. Moreover, light is an electromagnetic wave—which doesn’t need a medium and can travel through a vacuum; this is one of the reasons why in space… light remains visible, but there is no sound. Getting into waves… how do they move?”

Writing on the board, sound is categorized as longitudinal while light is… transverse.

“Sound is as simple as it can be, but familiarize yourselves with two terms.”

…Compression.

Rarefaction…?

“To easily explain it… imagine plucking a guitar string—pulling it out of its resting position then letting go. The string begins to vibrate back and forth rapidly, transferring kinetic energy to the air molecules surrounding the string,” she draws on the board. “As the string swings violently to the right, it pushes the air molecules on its right side forward. These molecules become tightly packed together; this region of crowded particles becomes a high-pressure zone called a compression.”

We nod… I glance at Hayashi whose eyes don’t leave the board.

“When the string passes its center point and swings in the other direction, the air molecules it pushes forward begin to spread apart… This creates a low-pressure region where the particles are far apart; this is called a rarefaction.”

So… compression refers to high pressure while a rarefaction is the contrary.

“Obviously, this doesn’t happen once—a guitar string will oscillate back and forth hundreds of times per second, producing a repeating sequence of compression, rarefaction, compression, rarefaction, until the vibration eventually fizzles out. The air molecules actually don’t travel across the room. Instead, they push and pull against neighboring molecules, allowing the energy of vibration to move forward.”

She pauses, pointing at the sequence of drawing.

“Eventually, those pressure changes reach your ear. They cause your eardrums to vibrate, and your auditory system interprets those vibrations as sound.”

…I see, hmm—

I raise a hand.

“Yes, Aihara-san?”

“Compression and rarefaction… is typically present when there’s vibration, right?”

“Yes, take anything that makes a sound—from a guitar string to the rustling of clothes. They all involve vibrations being transferred through particles. Look, the faster something vibrates, the higher its frequency. And of course, slower vibration—lower frequency. But the size of those vibrations also matters, because a greater amplitude means more energy is carried by the wave, and the louder the sound we perceive.”

Then, she draws an ear—some students laugh.

“Forgive my artistry,” she chuckles. “Your eardrums respond to the pressure changes from vibrations by also vibrating. Though, it has a limit to what it can comfortably handle. When a sound becomes extremely loud, those vibrations become much stronger, and the resulting pressure can become uncomfortable or even painful.”

…Painful?

“Like, when you hear a very loud sound, it can be interpreted as a sharp piercing noise. It doesn’t mean our ears are hearing more—they’re simply being subjected to much stronger vibrations.”

“May I… ah,” I raise a hand and she nods. “May I ask what examples usually lead to a sharp piercing noise…?”

“Hmm… a fire alarm, or a siren too, even those feedback from the microphone. Anything loud enough and close enough can become uncomfortable… leading to—anyways, we’re getting off track… light waves.”

Anything close or loud enough…

I wonder… no, I should be attentive.

“Now, light. Unlike sound, it’s a transverse electromagnetic wave…”

Maybe I should… ask her about it.

“By electromagnetic… it refers to not needing air or any material to travel through.”

Yeah, I hope she won’t mind.