Disclaimer: First Chapter
Story Start!

"Well, you don't have any friction burns, and you're STD free... so it doesn't look like you masturbate too much, or an STD is to blame. Though, considering how sensative to touch you are, I would say that you simply overused it. Are you in a relationship?"

Koneko was just smirking at Naruto the entire time that she was hearing this, seeing as Naruto was suffering from Shizuku being far too enthusiastic of a dick sucker it would seem. His scent didn't show that he had sex, and based on what he had been forced to admit to the doctor, the only answer that she could think of was Shizuku getting way to eager to do that to him. She also enjoyed Naruto's utter humiliation at having his junk probed and prodded by the doctor, though she wasn't allowed to be in the room when his junk was exposed.

"... Nooo... not technically..." Naruto forced the words out.

When he got home, Shizuku and Kuroka were in trouble. He knew that Kuroka sucked him off in his sleep sometimes, but since he was always asleep when he did it, he never made a giant deal out of it. As long as they didn't actually go all the way, he didn't care what they did in his sleep. Blowjobs were comparatively minor in the grand scope of the things he would have to deal with, but it would seem that he was going to have to seriously lay down ground rules on this.

"He has a weird relationship with a girl... that isn't me... I'm normal." Koneko pointed out with her smirk every once leaving her face.

She enjoyed being able to brag about that.

"You didn't notice that her actions caused this then?" The doctor spoke with a raised eyebrow, unable to understand why a boy this age didn't understand that when you had sex too much, you injured your penis.

It was kind of simple.

"I'm been on a really intense work out for a bit now... I just thought I pulled something, since I woke up like this." Naruto blushed crimson, annoyed that he was being questioned. When he learned of this from Kuroka, while he had been a tiny bit sore in the past because of her, she had never taken it too far. This was the first time he had woken up with this pain, so he had been worried. Not to mention, when considering how intense he had been working out, it was easy to assume that he had just hurt himself somehow during training, and was just now feeling it.

Koneko hated it, but she nodded in agreement, confirming that. He did have a pretty good excuse for why he would assume that something was wrong, but at the same time, he should have figured that Shizuku was to blame as well.

The girl was a fiend.

"Though, considering that you're a Demon Slayer-"

"Oh shit." Koneko realized what was about to happen the second those words were said, and the doctor's mouth stretched a little. She was about to make a move, before the doctor's neck stretched and wrapped around her, confining her into a state where she could barely move. She couldn't summon her strength to do much, other than struggle against the surprisingly powerful neck. "Naruto, she's a Rokurokubi!... She's an Ayakashi!" Koneko called out to him as the woman's head rushed towards him. The Rokurokubi's head was about to circle around Naruto, but he grabbed needle from the used needles bin, and stabbed it into the side of the doctor's neck.

"-ow!?" The Rokurokubi shouted as she loosened her grip on Koneko enough for the girl to get her hand free enough for Naruto to try and grab it. Naruto grabbed her hand, only for part of the neck to grab a hold on his hand as well. She wrapped her neck around Naruto too, and brought him inside of the coil that she had wrapped Koneko him, so that they were forced together. Naruto though, was hanging upside down with his head between Koneko's thighs, only able to breath because his face was not wrapped in neck. The Rokurokubi bit down on the needle in her neck, and pulled it out, before spitting it and glaring at both teens. "I wasn't trying to attack you, I need your help!" The Rokurokubi shouted at them, seeing as she had been called out before she had a chance to explain anything.

Why did everyone thing that all Ayakashi would attack a Demon Slayer at the first chance they had?

Since Naruto came into her office with a Nekoshou, she had thought that he would be willing to listen to her, but the Nekoshou had called her out and started something.

"I'm listening."

"I'm not." Koneko glared at the demon that had them trapped. She hated the fact that being trapped in bondage, aka tied up, and she wasn't going to help this demon no matter what she said. "Screw you, and screw you Naruto, I'm not taking you to the doctor every again." Koneko squeezed his head between her thighs. In response, Naruto kicked her in the side of the head for that one. The Rokurokubi seperated them, and gently set Naruto on the ground since he was willing to listen. She kept Koneko tied up though, so that she didn't get attacked.

"Just so you know, I'm not a good Demon Slayer, I still don't have any experience." Naruto pointed out, so that she didn't get her hopes up too high.

She nodded.

"I understand... You might have noticed I go my doctor Murano... but my real name is Toko. I became a doctor so that I could research the cause of Human/Demon relationships and how they work." Toko explained to Naruto to start it out with. Seeing as, despite being different species, Humans and Youkai could breed together, she as a woman of science had always wondered how that was possible. Not only that, but humans could breed with nearly every supernatural species as well. There were Human/Devil, Human/Fallen Angel, and Human/Youkai hybrids all over the world, though the human parent was usually kept in the dark about what their children were. "Or more exactly, I study human reproductive ability."

"What?" Naruto and Koneko asked, both a little dumbfounded.

"Humans have the remarkable ability to breed. As a Demon Slayer, I know you're aware that Ayakashi have extremely low birth rates on average, which is why we are also born with long life spans. Humans on the other hand, not only have extremely high fertility rates, but the ability to cross breed with every humanoid species. When two Youkai breed, the child is either one type or the other." Toko explained, since two different youkai didn't make hybrids, it was always one or the other for the children. They could technically breed together, but the birth rate was so low that nobody ever really tried to breed outside of their own race. "With humans, the children can be human with youkai powers, half-youkai, or full youkai with higher resistances to their natural weaknesses." Toko futher explained the topic of her research. The reason she became a doctor who specialized in the private regions of humans.

"Okay?" Naruto really didn't understand where this was going, or how he could help.

"Demon Slayers have human bodies, but supernatural abilities... but your abilities, unlike humans with supernatural powers... are completely unrelated to having non-human parents or Sacred Gears. Not to mention, Demon Slayers have far more vitality than a normal human. You're breeding abilities are a level above the average human. I would really like if you could donate semen and blood to me, so I can research a way to increase the fertility of Ayakashi." Toko have her request, since traditional human medications didn't work to increase the fertility of youkai. She hoped that if she studied a superior human's genetic material, the semen for obvious reasons, and the blood to get a basic genetic coding, that maybe she could create a miracle drug.

Naruto blinked.

"... That is actually a really tame request."

"I spent years blending into human society, unlike other youkai who spent their lives rejecting the idea of integration. I graduated medical school, top of my class, because I dream of a world where youkai don't have to take human forms. I've decided that to foster peace, I would sacrifice my own youkai instincts in order to create a better Japan for everyone." Toko had sparkles in her eyes. Thanks to her years pretending to be human, sometimes even tricking herself into thinking she was one, she learned what about human morals. She knew she could not expect Naruto to go and impregnate dozens of youkai women, just because it would further her own experiments by doing research on the children of such unions.

If he donated blood and semen to her on a semi-regular basis, she would have everything she needed to research and replicate the innate breeding ability of the human species, the humanoid species with the highest breeding capacity of all species who bore humanoid form. All youkai had a human form, despite it not being their true form, for the sole purpose of being able to blend in with humans, and breed with humans. Most super powerful species took on human forms, or at least had a human form, and that had always intrigued her immensely.

Why did so many powerful beings, decide to take on the form of beings many considered 'lower' than themselves?

She suspected that all supernatural beings, on some level, required the human species in one way or another. Devils, Fallen Angels, and Angels all drew their power from human desires and beliefs, the same with gods requiring human prayers to keep their strength up. Not to mention, many youkai were forced to seduce humans just to keep their own species from dying out. The humans were perhaps the most vital species on the planet for the supernatural world to continue running, and that was because of the vast number of humans, and their natural breeding powers. The human ability to adapt as well, which made them the species with more potential than any of the other species.

Not to mention, humans as a species, were the only species who had a natural ability to wield the weapons of gods, should those humans prove themselves worthy in one aspect or another. They were a species born with both light and dark affinities in some degree, making them able to use Holy Swords and Demon Swords if their affinity was high enough.

"You're drooling..." Koneko pointed out when she saw saliva drip off the woman's chin, and she quickly wiped it off.

She almost lost herself for a second.

"... I don't mind, but I won't do it for-"

"If you require sexual assistance, then I would be-"

"FOR A FEW DAYS!" Naruto shouted above her, since she was going to request something stupid. He didn't need her to help him, her goal was noble in nature, and he would be happy to offer her help. He just needed a few days for his body to heal before he could offer her any help. "What, don't have anything to say to this?" Naruto asked Koneko, since usually she would mock him for something like this.

Koneko was silent.

"... I..." Koneko, and she took a breath when she realized she could say this. "... think this is a very good idea, a lot of supernatural races could benefit from a drug like this... if she succeeds." Koneko hated admitting that Naruto was doing something good for society.

She just really hated the thought that Naruto's dick could create a bridge to a better future.

Chapter End!
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