The Slave Brand's Side Effect
The final exams were finally over. Now I could start my days without cursing the fact that I'd scheduled a first-period class. Most students, freed from assignments and lectures, were probably holed up in their rooms catching up on sleep.
"Ugh, fuck... it's so hot..."
At this ungodly early hour, I was already wiping sweat from my brow under the blazing morning sun. The asphalt burned beneath my feet as I walked, surrounded by rows of villas and studio apartments. This was the university's off-campus housing district. Most students who didn't live in dorms but rented their own places ended up in this neighborhood.
My cousin, Choi Go-eun—the one who'd accidentally seen me and Haemi last night tangled together—lived here too.
The memory of yesterday made me tug at my shirt collar, fanning myself to cool down. I retraced my steps from freshman year and before my military service, eventually spotting a familiar building.
"......"
Choi Go-eun's studio apartment. I stood in front of the one-room building and looked up at its tall frame. She was probably home. Go-eun hated the heat; there was no way she'd be out in this weather. I'd even texted her, 'Let's talk at your place tomorrow,' so it should be fine.
Of course, she'd left me on read.
I naturally recalled the passcode, punched it in, and opened the shared entrance door before climbing the stairs. It was a relief that Go-eun was the type who could keep her mouth shut. From the looks of it, my classmates, seniors, and even our parents had no idea what was going on. If she was the only one who'd seen it, I could probably persuade her somehow and clear up the misunderstanding...
But what the hell was I supposed to say to her?
......
Screw it. I'd just use the Slave brand to erase her memory. Yeah, that was the way to go!
No matter how much I racked my brain, the only future I could see was getting called a perverted bastard. In that case, even if it was unfair to Go-eun, borrowing the mask's power seemed like the better option. If she just forgot what happened yesterday, everything would go back to normal like nothing had ever occurred. She wouldn't have to remember seeing me half-naked either. It was a win-win. A perfectly peaceful solution.
Good. Perfect.
So then...
Ding-dong—
I knew the passcode to her front door too, but I deliberately pressed the doorbell instead. The clear chime echoed through the quiet early-morning hallway, followed by birdsong. When there was no immediate response, I rang it again.
Ding-dong—
"Hey, Choi Go-eun? You in there? It's me, Choi Woo-joo."
Clatter—!
Sure enough, I heard hurried movement from beyond the door. I'd been worried she might still be asleep since it was so early, but apparently she was awake. While I waited for the door to open, I dug at my ear and wiped the sweat from my chin. About twenty seconds passed. When it seemed like it was taking too long, I reached for the doorbell again.
With a loud clatter, the door finally swung open, revealing Choi Go-eun.
"...C-come... in... Hah, ugh..."
"...Hey, you..."
Her short hair was disheveled, her skin glistened with sweat, and her white tank top clung to her body, revealing deep cleavage. A wave of heat, humidity, and the sweet scent of a woman rolled out from inside the room. She stood there in nothing but that loose tank top and panties, both soaked through with some slick fluid.
"Hey, Choi Go-eun...?"
"...Hurry... come inside... please come in..."
Instead of her usual sulky expression, my cousin wore the face of a completely feral female in heat. She buried her face against my chest.
"Sluuurp... Haa...♡ Something's... weird... Choi... Woo-joo, your smell is so good...♡ Ugh... Ngh, ah? My head's going completely white... Clothes...!♡ Throw them away... Ho, huuugh...?♡"
"Hey, fuck...! Wait a second...!!"
Go-eun pressed her nose into my sweat-soaked shirt, inhaling deeply, her hips trembling violently. I pushed her inside the room before she could climax right there in the hallway. Thankfully, it was still early—no one had seen or heard anything.
But this...
"...Mmph, khuugh, huuup...♡"
Even with my hand over her mouth, Go-eun kept shuddering through orgasm after orgasm. Every time she came, the Slave brand on her forehead glowed brightly.
Why? Didn't that only shine when I gave a command? Why was it activating on its own...?
Anyway, I had to stop her first. At this rate, she was going to die.
"Sleep. Body and mind, completely."
"Huu... gh... ugh......"
I placed my hand on the brand engraved on Go-eun's forehead and infused it with coercive force. Her body, which had been thrashing like a freshly caught fish, gradually lost strength. Her eyelids drooped, and she collapsed onto the floor, fast asleep. I climbed off her and ran a hand through my hair.
Why the hell had she suddenly become like this? I'd noticed something was off yesterday, but...
While sorting through my complicated thoughts, I picked up the unconscious Go-eun from the floor and carried her deeper into the room. I couldn't just leave her on the cold ground until I figured things out, so I decided to lay her on the bed.
"...Whoa..."
The inside of the room was even worse. I couldn't hold back a gasp at the sight. Underwear and towels soaked with unidentifiable fluids were scattered across the floor. On the bed lay several sex toys, including a vibrator straight out of a porn video. The studio apartment of my cousin—my female friend—whom I hadn't visited since my discharge, had changed beyond recognition.
I kicked the toys aside with my foot, neatly spread out the blanket, and laid Go-eun on top of it. Through the hair covering her forehead, a jade-colored light continued to sparkle. The Slave brand was still glowing.
"It's probably because of that..."
No matter how I thought about it, the most suspicious thing was that brand. I opened the small bag slung over my shoulder and pulled out the mask. Swinging it around like a fan, I spoke to it.
"Hey, you've drunk more than five liters of alcohol since then. That's enough for you to talk, right? Just for a second, tell me why she's acting like this. It's not that hard, is it? We're friends, after all."
Staring at the glowing light wasn't going to magically reveal the cause or solution. When you're sick, you go to a doctor. When you need legal advice, you go to a lawyer. For something like this, you ask the mask. After all, this was the same mask that had engraved the brands on both Go-eun and that call girl Dasom before. I figured I might as well ask why it had imprinted those characters on humans' foreheads while I was waking it up.
In the sweltering room, I fanned myself with the mask, muttering, "Wake up, you idiot," until I finally got a response. The mask began vibrating in my hand like a phone on silent mode. When I stopped fanning, it sprang up like a jack-in-the-box, leaping out of my grasp. Then, with a soft clack, it landed directly on Go-eun's face.
Hey, wait a minute.
"It's been a while since I've used this woman's body... The last one was lighter, but this one's not bad either."
"...For starters, she's my family, okay? Stop evaluating her body and just tell me what the hell you did."
Like a possessed person from a horror movie, Go-eun's sleeping body slowly rose. But the one stretching her shoulders and speaking wasn't my cousin Choi Go-eun—it was the mask wearing her body.
"...Hmm, you still haven't touched this body yet? I even went out of my way to mark it for you."
"...What the hell are you talking about? Explain properly. Marking? Is that why she's turned into a horny monkey?"
I snapped at the mask as it used Go-eun's hands to grope her own breasts.
"Fanatics already know this, but now that I think about it, I never explained the brands to you, did I? The brands are the strange characters written on my true form—the back of the mask. They're not Korean, so they're hard to read, right? Through them, I can turn human women into Saintesses, form contracts with men who will become their masters, and so on. They have many functions."
"...So the 'Slave' you engraved on Go-eun literally means slave?"
"That's right. When I branded this woman named Go-eun, I didn't have much power left, so I used a simple character. Anyway, depending on the meaning of the written brand, it has the power to modify humans. It's not very useful to me, though. Well, if you want, you could use it to modify humans or Saintesses and enjoy all sorts of plays... but for me, engraving brands on humans has no special meaning. I was simply marking them."
"...Marking?"
"Marking. Preparing bodies that would be good for me to possess later, when I eventually obtain my own physical form. If I mark them in advance, I can reference their height, proportions, appearance, voice, and so on. Hehe..."
So the characters engraved on the mask could be imprinted onto humans or Saintesses, and depending on their meaning, they had the power to modify bodies and minds. The mask had simply marked Go-eun and Dasom as references for the body it would eventually create for itself...
"...But why Choi Go-eun of all people? What was there to reference...?"
"...Didn't you say this woman is your family? That reaction seems a bit excessive. You might not know this, but her body is incredibly healthy. She'll probably live to a hundred without getting sick."
"You can tell that too? What about me?"
"I've never used your body, so I wouldn't know. I hate male bodies anyway! First of all, quit smoking. At your current pace, you'll be in the early stages of lung cancer soon."
"......"
Shit. Go-eun was healthier than me, but I was the one getting lectured...
"Anyway! So it's because of that brand that Go-eun became like this! Why is this happening? If it was just marking, can't you just erase it?"
"I can't. Once it's engraved, even I can't remove it. And the reason this woman is in heat is a side effect of the brand."
A giggling voice came from beneath the mask, using Go-eun's throat. The mask reached down, pulled her panties aside, and spread open her dripping wet pussy.
"Hey, what the hell are you—!"
"The power of the brand is eternal. The eternally enduring power of the brand is strong enough to change a human's body and mind. What I engraved on this woman was 'Slave.' In other words, her thoughts are gradually transforming to match that of a slave. If you leave her like this, things will get serious. If someone speaks to her in a commanding tone after she's been completely modified into a slave..."
"......"
Choi Go-eun would obey that command...?
"If some greasy old man she doesn't even know tells her, 'Go out with me,' she'd happily date him. If someone tells her to die, she'd slit her wrists without hesitation. Is that okay with you?"
"Of course not."
Listening to the story, I spat out a short curse, my mood turning extremely foul. But the mask, laughing as if it didn't care about my trembling voice filled with rage, grabbed my hand.
"I was just describing the worst-case scenario, so don't get too angry. There's still a way. A way to erase the brand. The reason she threw herself at you in heat is an early symptom of the modification. It's giving priority to her master, which means it's still at a stage where it can be fixed. Of course, if the brand completely settles into this body, rewriting it would become impossible, but..."
"...What is it? Hurry up and tell me."
As I glared at the mask in irritation and disgust, something wet touched the fingertips it had stolen. It was a pussy completely soaked with love juices. It was Go-eun's—my own blood relative's—hole.
"You've already rewritten a brand before, haven't you? That woman named Dasom... I had engraved Depravity and Modification on her, but you changed it to Fanatic."
"Wait, you don't mean..."
"That's exactly what I mean♡ Have sex with this woman. Turn her into your Fanatic. That's the only way♡ Oh, you're not worrying about ethics or something, are you? If you worry about that, your family might end up as someone else's slave, you know?"
The mask, moving Go-eun's body with playful gestures, laughed brightly while using her fingers to masturbate.
A moment of hesitation. Was this really the only method? Wasn't there some other clever solution...?
Clack—
Something new fell into my line of sight, which had been directed downward at Go-eun's pussy. It was the mask, which had slipped off her face and was now rolling across the cold floor.
I slowly raised my gaze. To the face of Choi Go-eun, now freed from the mask.
Our eyes finally met, and there—
"...Huh? E-eh...? Choi... Woo-joo...? What are we... right now... Ah, no, just now at the front door...! We can't do this... Huh? I must have gone crazy for a second... So please, take your hand away...!"
For a brief moment, I saw Go-eun's face—scolding herself for nearly crossing a taboo due to a sudden burst of lust and the brand's side effects. Her face was flushed bright red, fear evident in her eyes, and she was trying to pull my hand away from her crotch. Yet even then, the glowing Slave brand on her forehead caught my eye.
There was no time. No other method.
"Hey, Choi Woo-joo...! Are you listening?! Take your hand off! If you don't, I'll scre—"
Squelch!
"Nghik?!♡"
My fingers parted her slick, wet vaginal walls. They were warm. And they squeezed tightly.
"What the hell are you—!! Ngh-chuuup——?♡"
"Haa... Be quiet. I'll finish this quickly."
I thrust my fingers into Go-eun's pussy, which was twisted in shock, and pressed my lips against hers. The sweet taste, laced with a sense of taboo, lingered on my mouth. After wiping my lips once, I kissed her again and pushed the resisting Go-eun onto the bed.
* * *