As I walked around the academy grounds, it was already nearing the end of the final period.
So I left behind the places I hadn't seen yet and headed back to the classroom.
As I walked through the empty hallway, a familiar figure appeared ahead of me. It was my homeroom teacher, Iseol noona.
She spotted me, seemed to hesitate for a moment, and then approached me.
“Sihyeok, do you have a moment? There's something I'd like to discuss with you about the practical class on caressing starting tomorrow.”
After checking that no one was nearby, she lowered her voice and continued.
“Normally, students practice in practical classes using silicone models. There are few men, after all, and many of them feel uncomfortable exposing their genitals in front of women.”
Iseol noona's face flushed slightly as she got to the main point.
“Still, if you're willing, Sihyeok, I was wondering whether you could serve as the male practical model for our class. Nothing makes for better education than directly experiencing how a living man responds. It would be an incredibly valuable opportunity for everyone.”
Perhaps worried that I might refuse, she hurriedly began explaining the benefits.
“Of course, I'm not asking you to do it for nothing. The academy understands that serving as a practical model can be difficult, so they're offering several forms of support.”
She spoke while counting them off on her slender white fingers.
“First, you'll receive a fairly generous special scholarship. In addition, we can adjust some of the practical exercises to suit your preferences… and you can even choose your own practical partner.”
Her gaze met mine directly.
“Any woman you like will do. Chaerin, Subin… or even me.”
Her eyes glittered with anticipation. As she spoke the final words, she asked almost in a whisper.
“What do you think, Sihyeok? Could you… serve as the practical model?”
I heard something explode inside my head.
They wanted me to be a teaching aid in practical classes on caressing and sex?
Did that mean all the female students in my class might jerk me off, give me blowjobs, and perhaps even have sex with me?
Note or no note, this was an offer I simply couldn't refuse.
I cleared my throat once and answered in as calm a voice as possible.
“If it's for everyone's sake, I suppose it can't be helped. I'll be the practical model.”
Iseol noona's face lit up at my answer.
* * *
When class ended, I left through the school gates with Chaerin and Subin.
There were plenty of other people heading home before it got late.
The female university students' outfits stood out today as well.
Back on Earth, female university students wore outfits so slutty they couldn't have objected to being called sluts, yet they strolled down the streets without a care.
If the weather got just a little warmer, I felt like I'd see plenty of naked women too.
Near the main gate, expensive-looking imported cars were lined up.
Men with relaxed expressions sat inside them while countless women fawned over them as if competing with one another.
It was a world completely separate from mine, where I got around on foot.
We headed home while talking about how our major classes had gone that day.
On the way, Subin carefully asked Chaerin and me a question.
“Guys, do you want to have dinner at my place tonight?”
I was briefly surprised by Subin's suggestion, but I soon guessed what she meant.
HSDD. The thing I'd asked her to tell me about during Kegel class. She'd invited us over so she could explain it.
To get closer to the truth behind the note, I needed to gather as much information as possible from the people around me.
I also intended to ask about that suspicious cult, not just HSDD.
Subin's house was right next to mine, but its atmosphere was worlds apart.
After passing through a neatly tended little garden and opening the front door, we were greeted by warm lighting and a faint floral scent.
It was far too spacious and cozy to be a house where only Subin and her mother lived.
Expensive-looking paintings hung on the walls, and a grand piano with sheet music on it stood in one corner of the living room.
“I guess your mother hasn't gotten home from work yet?”
“Yeah, she's going to be a little late today. Make yourselves comfortable.”
Subin showed us to a plush sofa, then went to the kitchen and brought back orange juice and fancy cookies.
It was my first time at Subin's house, so I felt awkward, but Chaerin seemed familiar with the place and immediately found a board game beneath the living room table.
We sat around the table and started playing. It was a simple game where you rolled dice and bought land.
Chaerin was highly competitive, so every time she rolled the dice, she shouted in delight or disappointment.
Subin merely smiled quietly as she watched Chaerin. Genuine happiness showed in her expression.
Only then did I realize that the two of them were quite close. They had apparently lived in the same neighborhood since they were young, so they must have been very close.
After the game had gone on for quite a while, Chaerin, who had lost, rose from her seat.
“I need to use the bathroom.”
Once Chaerin disappeared down the hallway, only Subin and I remained in the living room.
The lively atmosphere subsided, leaving behind a silence that wasn't unpleasant.
I thought this was my chance, so I carefully broached the subject with Subin.
“Can you tell me about the illness you said you'd explain after school—the one called HSDD?”
Subin's expression stiffened slightly at my words. She fidgeted with the cup in her hand, hesitating for a moment.
The only sound in the living room was the unusually loud ticking of the grandfather clock.
At last, as if she had made up her mind, she spoke in a quiet voice.
“That… is something Chaerin already knows about, too.”
Her gaze remained fixed on the floor.
“HSDD stands for hypoactive sexual desire disorder. You can think of it as a hereditary disease passed down through my family.”
Subin tried to explain as calmly as possible, but her voice trembled faintly.
The tremor carried loneliness and sadness I knew nothing about.
“As you know, women have incredibly strong sex drives. That's considered normal. But my family isn't like that. We can go without masturbating every day like everyone else, and we don't get wildly aroused just by seeing a man.”
She paused and took a deep breath.
“So ever since I was little, people have treated me like a strange girl. Other girls teased me, calling me frigid or a block of wood… and men showed no interest in me at all.”
Clear sadness welled in her eyes.

“So I have no friends. Except you and Chaerin.”
Something in my heart ached at Subin's confession.
Only then did I remember the health teacher's reaction—the way she'd turned cold the moment she learned that Subin had HSDD.
HSDD seemed to be treated as a kind of defect, disability, and stigma.
It finally made sense why Subin's pussy, unlike the other women's, had barely gotten wet during the physical examination, and why she'd looked so pitiful as she tearfully called her own body disgusting.
When everyone else viewed the world through the single eye of sexual desire, she had been born with a different one.
HSDD was a two-eyed person persecuted in a one-eyed world.
A minority the majority cannot understand is always destined to be ostracized.
“Subin.”
My voice had grown infinitely gentle without me realizing it. At the sound of my voice, Subin, who had been staring at the floor, lifted her head.
And then I noticed it: the deep fear that had settled in her emerald eyes.
Subin wasn't merely surprised or flustered; she was afraid.
She was afraid that, now that I knew she had HSDD, I would despise and loathe her like everyone else and eventually push her away coldly.
The moment I saw her eyes, I could imagine what sort of life she must have lived until now.
A life in which her friends pointed fingers at her, her teachers failed to understand her, and the adults turned their backs on her.
And yet, despite all those fears, Subin had told me the truth.
Even while trembling at the thought that I might abandon her and leave her alone again, she hadn't run away or hidden herself.
Instead, she had bravely exposed her painful, shameful wound before me.
Why? Guilt because she didn't want to deceive me, her friend? Or a hope that I would understand her as she was?
It didn't matter which answer was correct.
Something hot surged up from deep within my heart.
It was a mixture of being deeply moved, guilt, and a fierce protective instinct to keep her safe.
I no longer hesitated. I wanted to put an end to her fear.
I rose, sat beside Subin, and very carefully and gently stroked her hunched back.
I did so with the utmost care, as if she were a fragile piece of glasswork.
“Why, why are you doing that… Sihyeok? Did I do something wrong?”
“No. I just wanted to hear more. About HSDD.”
At my words, I watched the color drain from Subin's face. With her head bowed deeply, she whispered in a voice that was almost inaudible.
“Why…?”
“If you're all right with it, I'd like you to tell me. About HSDD, and about the parts of you I don't know.”
I said nothing and continued stroking Subin's back, waiting until she felt ready to speak.
A brief silence passed. Then, as if she had made up her mind, Subin slowly opened her mouth in a voice thick with tears.