The Secret Behind the Growth
Hunters’ world. “It’s not impossible.”
Lee Seon-yul, who had been standing there with a blank expression, snapped back to attention at Do Hyun-ah’s voice.
“…So you’re saying she really got stronger just from sex… like Kim Hee-jung said?”
“There are cases where the mana circuits inside the body get altered through sexual intercourse between a man and a woman. There are papers on it. China has its bedroom arts, Hinduism and Islam have their own traditions, and Europe has been researching it seriously.”
“That’s ridiculous…”
“Of course, if just having sex was enough to grow stronger, hunters wouldn’t bother training so hard, spending fortunes on elixirs, or absorbing mana stones.”
Do Hyun-ah continued her explanation in her usual emotionless tone.
“The conditions are strict. First, their mana must not clash. In other words, their compatibility has to be good.”
“……”
“Second, the person has to be capable of freely manipulating mana to the point where sexual intercourse can actually reshape the circuits—or be born with that kind of constitution. Because the exchange of fluids lets them share mana, and that’s what triggers the change.”
Do Hyun-ah tapped her temple with her finger, as if thinking.
“Jin Seong-ah is a physical-type. She has almost no ability to project mana outside her body, so her partner—whether male, female, or some other living being—must be extremely skilled at handling mana…”
“……”
“If she really formed a relationship with someone like that, then this sudden surge in strength makes sense. Her internal circuits simply adapted to her body. It’s like someone who’s been limping their whole life suddenly being able to walk normally.”
“How many people like that even exist…”
“Aha.”
Having picked up on something from their conversation, Kim Hee-jung lowered her head toward Jin Seong-ah and whispered, barely moving her lips.
“Seong-ah, you… don’t tell me…”
“……!”
“I knew it! Oh my, oh my… Oh dear… I had a feeling…”
Jin Seong-ah’s face, already flushed, turned an even deeper shade of red, like a kettle about to boil over. Seeing her reaction, Lee Seon-yul blinked several times in disbelief before stepping closer.
“Jin Seong-ah.”
“Y-yes…?”
“You… ha, I know this is embarrassing, but let’s clear this up. Did you really have sex?”
“……Yes.”
“How many times?”
Do Hyun-ah asked from the side.
“H-how many times…? Why does that matter…?”
“The number matters.”
“The… number…?”
“Think of it like rehabilitation exercises,” Do Hyun-ah said, looking down at Jin Seong-ah with her usual blank eyes. “Normal training gives results proportional to effort, but rehabilitation is different. It’s about restoring the body’s original functions. Since we’re correcting unstable mana circuits inside the body, once you pass a certain number of sessions, the growth will stop.”
Jin Seong-ah, who had been keeping her head down with her face bright red, glanced up at Do Hyun-ah.
“W-when you say… number of times…”
“Mm.”
“Does that… include everything…?”
“Since the exchange of saliva counts, even kissing works. Regular intercourse, oral sex, anal…”
“Aah, aahh…”
Unable to endure the embarrassment any longer, Jin Seong-ah covered her face with both hands and sank to the floor.
“It’s fine. Everyone here knows how to keep a secret…”
“Oh my, Hyun-ah? Why are you looking at me like that?”
“……You turned the camera off, right?”
“Of course!”
Remembering all the videos Kim Hee-jung’s team uploaded to the guild’s SNS channel, Do Hyun-ah hesitated for a moment. The important thing was that someone was keeping watch.
“…We know how to keep secrets. You can tell us. Or you can come find me later and say it privately.”
“Haaah…”
After rubbing her face, Jin Seong-ah spoke in a tiny, shrinking voice.
“…I don’t know.”
“……?”
“I don’t really remember… how many times…”
“Oh my, Seong-ah…”
Feeling dizzy from Kim Hee-jung’s dramatic reaction, Lee Seon-yul turned to Do Hyun-ah.
“…You said Europe is researching this?”
“They’ve been sexually open since before the Gate incidents. Places like the Paris Autonomous Region, the Berlin Republic, and Sweden have been conducting serious studies. The UK too.”
“Instead of falling apart because they can’t hunt monsters, they’re busy doing this kind of research…”
“Sex is easier than unification.”
“True.”
Do Hyun-ah delivered the vulgar joke without so much as a blink, and Kim Hee-jung immediately agreed. Lee Seon-yul felt her energy draining as she asked again.
“Is it real?”
“Why would I lie?”
“It’s just… I’ve never heard of this field before. Is it really true?”
“About half?”
Lee Seon-yul’s brow furrowed.
“This whole field started from superstition in the first place. Back in the day, high-ranking female hunters in China would capture male hunters under the excuse of bedroom arts and lock them up…”
“…Female hunters?”
“Women have the advantage when it comes to absorbing fluids. Men can only use their mouths at best…”
“Stop describing it in detail. Anyway… you’re saying female hunters have an easier time growing stronger this way?”
“Probably?”
Do Hyun-ah shrugged.
“I’ve never researched it myself. I’ve only read a few papers, and unlike before the Gate incidents, Europe isn’t producing authoritative papers anymore, and China’s research isn’t trustworthy.”
“…What if you researched it yourself?”
“Assuming I can find someone who meets the conditions I mentioned and they agree to cooperate, I could probably get some results. Looking at Jin Seong-ah’s case, there’s a high chance we’d get positive data.”
Lee Seon-yul turned toward Jin Seong-ah.
“Jin… I mean, Seong-ah.”
“Yes…?”
“Can you tell us who your partner was?”
“Ah, that’s…”
“You heard what Do Hyun-ah said, right? If you really got stronger through sex, we could get meaningful data. For that, we’ll need your cooperation—and your partner’s. Of course, we’ll compensate you both…”
“……It’s my senior.”
“Senior?”
Most of the hunters in Yushin Guild were Jin Seong-ah’s seniors. However, hunters below S-rank treated her like an upperclassman because of the massive gap in their ranks. So the kind of person Jin Seong-ah would call “senior” within the guild… and a man at that.
“Don’t tell me it’s Yu Seong-eun?”
“Yes…”
At that moment, a memory flashed through Lee Seon-yul’s mind. When Jin Seong-ah had destroyed the training facility and she had gone to find Shin Ji-hye. Yu Seong-eun coming out of the guild leader’s office while Shin Ji-hye hurriedly fixed her clothes.
“Crazy.”
It felt like her chronic migraine was coming back with a vengeance.
#
“Are you two dating? Since when? Don’t tell me it was already happening when you were on the same team?”
“W-we’re not dating…?”
Kim Hee-jung made a fuss as she dragged Jin Seong-ah away. Watching their retreating figures, Do Hyun-ah muttered.
“At this rate, the whole company’s going to find out.”
“……”
Despite possessing S-rank power that defied all standards, Kim Hee-jung had volunteered to run the marketing team—a job any ordinary person could do. She loved gossip and had a meddlesome side. Still, she was thorough about keeping secrets when it mattered…
Do Hyun-ah figured Kim Hee-jung probably wouldn’t let Jin Seong-ah go until she’d heard every last detail about how she ended up in that kind of relationship with Yu Seong-eun.
While she was thinking this, Lee Seon-yul, who had been sitting on the floor clutching her head, spoke in a weak voice.
“Do Hyun-ah.”
“What?”
“I need healing.”
“It’s called treatment, not healing.”
Even as she said this, Do Hyun-ah gathered her mana. A pure white light that almost looked sacred formed into a small mass and seeped into Lee Seon-yul’s head.
“……Ghk.”
“Also, migraines have psychological factors too. Relying on treatment isn’t good.”
“I know that.”
The migraine that had felt like someone was stabbing her head with an awl disappeared. In its place came a pain like needles pricking her entire body, but Lee Seon-yul gritted her teeth and endured it. Once the pain from Do Hyun-ah’s ability subsided, she barely managed to open her mouth.
“You said… there are papers, right…?”
“For now.”
“You said they weren’t authoritative. How good are they?”
“They’re not published in academic journals. They’re just circulating among researchers. Basically graduate thesis level.”
“……”
“Why? Want to read them?”
“Do you have them?”
“They should be on my computer.”
“…Let me see them.”
“Got it.”
Do Hyun-ah stood up. Seeing Lee Seon-yul silently following her, she spoke quietly inside the executive-only elevator.
“I understand why you’re looking for those papers.”
“……”
Lee Seon-yul’s growth had stopped several years ago. Even so, she was still one of the top telekinetic users, but it was a fact that tormented her like a reverse scale. In emergencies, even Kim Hee-jung and Choi Mi-ra—who worked in non-combat departments—were sometimes deployed to the field, but Lee Seon-yul was completely excluded.
“Senior might actually be capable of it.”
“…I know. Even though he’s D-rank and a mental-type, his ability to handle mana is on par with most magic-types. But changing circuits through bodily fluids…? Does it make sense that he’s reached that level?”
“He probably didn’t do it consciously. Senior has several parts of him that aren’t biologically human.”
“Not human. You mean he’s closer to a monster?”
“Yeah.”
“…I’ve heard that when monsters and humans have intercourse, the human side sometimes absorbs mana.”
“So theoretically, it’s possible.”
Emphasizing that it was only theoretical, Do Hyun-ah spoke calmly.
“Still, don’t get your hopes up too much. Your situation is different from Jin Seong-ah’s.”
“……”
“Jin Seong-ah is still immature as a hunter. She’s like a child who’s just started walking. In contrast… you’re already an adult. Unlike the physical-type Jin Seong-ah, you’re a magic-type, so your internal circuits are…”
“I know.”
Her answer came out like she was chewing on the words. It was the limit of what she could accept as advice. Do Hyun-ah understood that.
“T-Team Leader…! You’re here…?”
“Why? Did a patient come in?”
“N-no…”
“Really? Then keep working.”
Do Hyun-ah said this to the staff member who had jumped up from the counter and guided Lee Seon-yul into her office.
“……”
“……”
An awkward silence filled the office. Sitting at her desk, Do Hyun-ah searched through her computer folders, found the paper, and printed it out.
“Here. It’s in English, but that’s fine, right?”
“…It’s fine.”
“Like I said, it’s an unverified paper, so read it with some skepticism. It’s just a theory that hasn’t even been tested—basically at the level of wild speculation.”
“…Right.”
Clutching the paper tightly, Lee Seon-yul left the office.
“……”
Watching her go, Do Hyun-ah thought to herself.
Thank goodness.
Baek Seol, the leader of Team 1, had also stopped growing, but for some reason she didn’t seem to care at all. Was it because she was still overwhelmingly strong even in that stagnant state…?
Probably not.
Only Guild Leader Shin Ji-hye knew Baek Seol’s circumstances. Even Yu Seong-eun, who had been a founding member alongside Shin Ji-hye, knew nothing beyond the fact that she was a returnee. Maybe he knew more but simply chose not to say anything…
But one thing was clear: Baek Seol was broken somewhere.
She was more like a doll than a person.
It was fortunate that Lee Seon-yul hadn’t broken down like Baek Seol. Fortunate that she still possessed the instinctive hunter’s desire to grow.
#
After delivering the usual morning sandwich to the guild leader’s office, I entered my own.
“Oh my, Seong-eun. Good morning?”
“Ah, yes…”
Since I was part of the Guide Team, it was natural to run into Choi Mi-ra, the team leader, on my way to my office. Aside from the slight awkwardness of knowing she could read my thoughts just by looking at me, it was a peaceful morning.
‘She wouldn’t read my thoughts down to the unconscious level, right?’
It had been a week since I started living with Shin Ji-hye and Jin Seong-ah. Every night I diligently trained the two of them, and our days began with sex the moment we opened our eyes. Thanks to that, I hadn’t been accumulating the usual sexual frustration or having strange thoughts in the morning. Even when I saw Chae-eun on my way back from delivering the sandwiches, I didn’t feel anything, so at least that much was certain.
‘Is “diligently” the right word?’
Well… I’d managed to significantly suppress Shin Ji-hye’s suicidal impulses. I’d also succeeded in controlling Jin Seong-ah’s violent desires to some extent. The methods were lewd, which made it feel that way, but I was steadily making both of them more stable.
‘I still need to calm Shin Ji-hye down a bit more…’
When she brought Jin Seong-ah to me, I had read her desires.
……She wanted to offer all the guild’s S-rank hunters to me so I could steal her guild from her. I was the one who had twisted her into finding pleasure in social death rather than physical death, but I hadn’t expected her to twist in that direction. I was suppressing it as much as possible, but the problem was that it occasionally surfaced at completely unexpected moments.
‘That’s a bit…’
The little devil in my head was saying that a harem was the only proper choice for a man and urging me to just go for it. Considering how my body held up even though I was having sex almost all day after work, maybe increasing the number wouldn’t be a problem. The issue was whether I could handle it.
Among the remaining S-ranks, the only one who listened to me well was Do Yoon-ah at best. From Baek Seol and Do Hyun-ah, whose usual thoughts I couldn’t even guess, to Park Ha-neul with her temper…
‘Make a harem out of those people?’
Walking on thin ice would probably feel less dangerous.
For now, my goal was to suppress Shin Ji-hye’s bizarre desires as much as possible.
“Then…”
While I was deep in thought in my office, the door suddenly burst open without any knock.
“Hey. Yu Seong-eun.”
“…What are you doing here?”
I wondered who would come find me without knocking, but to my surprise, it was Lee Seon-yul who walked in.
“You…”
“Yeah.”
“You, you…”
Why was Lee Seon-yul, who almost never left the research and development team, coming all the way to the Guide Team just to point at me? I didn’t know why, but she looked furious. Her usual listless expression was gone, her face was bright red, and she was trembling as she glared at me.
“You, with me…”
“What? Spit it out.”
“……”
“……?”
“Fuck.”
She suddenly cursed, slammed the door shut with a bang, and stormed out.
“What the hell.”
Why was she acting like that toward me?