Special thanks to @QuestOverlord for this amazing omake.
Only reason it is semi-canon is that Kuroka did not make the cut for my personal waifu list, otherwise the sidestory is canon compliant and wonderfully written.
TLDR: This isn't canon but if I wanted Kuroka it would be canon. Basically it's an If-Route
As Kunou and I were training outside my base, the wards pinged a powerful signature in a clearing near town, nearly ultimate class.
"Looks like someone wants to meet me. Strong high class signature nearby, waiting patiently. Go inside, I'll keep you updated."
Kunou nods. "Be safe!"
It only took a few flash steps to appear in the clearing, my strength growing by leaps and bounds as my Ki continued to increase in density and purity.
"Who goes there!"
Hey, we watched Monty Python last night, sue me.
The…yokai devil? with black cat ears smiled before opening her mouth to speak.
"My name is Kuroka, you may have heard of me nya~. The organization I'm currently part of wishes to request your cooperation in returning the True Longinus to its bearer."
Oh boy, this is going to be a nightmare, isn't it.
"And what organization would that be?"
"The Khaos Brigade. I'm part of Vali's Team, but it seems the Hero Faction got on your bad side nya~."
"…they tried to kill my girlfriend and chop up my daughter for parts."
She recoils in very visible shock at that. "Alright, his injuries were deserved then? Good! I hate that guy anyway!"
I chuckle a bit. "No honor among thieves?"
She scoffs. "Half of these guys are barely more than slobbering monsters anyway nya~. Many members joined so they could get away with killing civilians!"
"And why did you join?"
"My sister."
I cross my arms. "Gonna need you to be more specific."
She hesitates for a moment before opening up to me. "My sister is still with the devils. Long story short, I joined to cause disruptions in the hope of being able to recover her in the chaos…"
After thinking for a moment, I shoot Kunou a quick text. "…why don't you come back to my place. You can explain to Kunou and I together."
"Ooh, meeting the princess! How exciting nya~" she jokes, moving to follow me.
—
"I didn't expect a Sage to actually live in the woods nya~." She said, a bit in awe at the tree base.
"No, I live at my house. This is my office, meeting room, and research lab!"
She giggles, walking inside with me. I'm glad I listened to Kunou's insistence and construct a meeting room, even if I'm pretty sure she only wanted it so she could fuck me here too instead of needing to wait until we got back home…
"Ooh, nice place nya~"
Kunou, who had been waiting for us, cleared her throat. "I believe introductions are in order-?"
"Kuroka, you may have heard of me nya~!" Kuroka responded, making Kunou step back and gasp.
"T-the ultimate class stray devil?! Aren't you a terrorist!?"
I quickly interceded. "Calm down, she was only here to deliver a message, I brought her here because I wanted to hear more about what brought her to join this…organization."
After composing herself for a moment, Kunou nodded. "Right, come sit down." We all moved over to a set of opposing wooden benches with a low table between them, Kunou sitting next to me in the one closest to the wall while Kuroka sat opposite us. "Since I wasn't there for your conversation, could you start from the beginning?"
Kuroka smirked. "Of course nya~! When a Nekoshou named Fujimai loved a human researcher VERY much-"
I held up my hand and cut her off as Kunou seemed lost in thought. "Could you maybe skip ahead just a little bit?"
With a cute giggle, she resumed speaking. "My sister, Shirone, and I lived with our parents, a Nekoshou named Fujimai and a human researcher, though we never really understood clearly what it was he did nya~. He…didn't acknowledge us, and he barely interacted with our mother, outside of enlisting her assistance in the lab or…in the bedroom." She gestured to herself with chagrin.
I felt a growing sense of unease and noticed Kunou was biting her lip in consternation too.
"One day, there was an accident in the lab, and…our parents…never came home." She took a deep breath in and out. "We were taken in by our father's coworkers though."
"Who were they?" Kunou asked quietly.
"Devils of the house Naberius…" she responded, making Kunou visibly wince.
"Is that when-"
"When I was turned into a devil?" She gave a forced smile. "Yes, the King of the peerage granted me two Bishop pieces…"
Kunou paused for a moment and quietly asked. "To either of you…did they…?"
Kuroka shook her head vigorously, making Kunou sigh in relief. "No, they were actually serious about making me a powerful peerage member nya~! They trained me in magic and I continued practicing Senjutsu and Youjutsu that I learned from our mother while I was taking care of my sister…"
I broke her momentary pause. "I'm sensing there is a 'but' coming…"
She nodded and bit her lip. "Everything seemed to actually be going well, and then one day they…they-" her voice cracked and she bit her lip, prompting Kunou to slip over to the bench next to her and gently take her hand. "T-thank you…they told me they were going to use my s-sister as…research materials for the creation of super devils…"
We all sat quietly for a moment as she quietly grimaced, obviously reliving very unhappy memories. "…you know, you don't have to go into this much detail if it's too painful…"
After a moment's thought, she shook her head. "N-no. No. I think it…it would do me good to open up to someone about this." She forced a small laugh. "And who better to talk to than the Sage nya~."
Kunou nodded and squeezed her hand, gently coaxing her to continue. "Then you kicked his ass, right?"
Kuroka laughed dryly. "You bet your ass I did nya~! The King hadn't realized how powerful I actually was, so I tore him to pieces easily…but my sister saw me, and…she was…terrified. I made my escape, but I couldn't bring her with me, and she was kept under tight security from then on…the official word was that I had gone mad with power and killed my King for no reason, so that's probably what she thinks happened…"
After a minute or two of silence to let her calm down, I asked another question. "So, where did you go from there?"
She giggled. "Oh, all over the place nya~! Since I was on the run, I got REALLY good at convincing simpletons I was going to blow their minds in the morning if they let me spend the night and rest-"
"Only for them to realize you left before they woke up?" Kunou grinned as she finished Kuroka's sentence.
"Exactly nya~!" Kuroka laughed, squeezing her hand. "A lesser yokai might not have managed that with her chastity intact nya~."
I sighed loudly. "So how did you end up joining the Chaos…Khaos? Is this Khaos with a K?" I asked curiously.
"Yeah, how could you tell nya~?" Kuroka questioned in kind.
"Well, from the way you were describing them, they sound a little…"
"Extra?" Kunou helpfully butted in.
"Well, I was going to say pretentious, but extra works too…"
Kunou and Kuroka both laugh at the dry joke, visibly relaxing in each other's presence, prompting Kunou to return to my side.
"Well, in my travels I ran across a half-devil named Vali Lucifer, the White Dragon Emperor nya~." An exasperated grin decorated her face. "I thought he was there to kill me or bring me in, but he just wanted a fight, and when he realized just how good I was, he invited me to join him nya~."
"And what did he want to accomplish?" I ask, more intrigued.
"Well…" she trailed off, deep in thought. "He never elaborated what his actual end goal was, but judging by the fact that he's a real full-blooded Lucifer and he won't recruit any Sacred Gear users, he probably wants to kill his grandpa, nya~."
I have a bad feeling about this. "Who is his grandpa?"
"Rizevim Livan Lucifer nya~."
Kunou bristled instantly and I turned to her. "Who is that again?"
"The first son of Lucifer and also the first Super Devil. He can deny God's Authority over those granted His gifts, disabling the usage of Sacred Gears…" she whispered, almost trembling. I wonder if she was taught to fear him as a child.
"So what you're saying is, since Vali uses a Sacred Gear, he can't fight Rizevim, but he's recruiting people that don't have them to kill his grandpa for him?"
She sighed. "That seems to be the long and short of it nya~."
"Are you trying to recruit me for him?" I asked, feeling Kunou go still beside me.
"Nah, you have a mate and a child, his group is for disaffected people that want to turn the world upside down to achieve something personal to them nya~."
Kunou chimed in again. "Is there anything else you wanted to achieve from joining his group?"
Kuroka gave a wry smile. "Well, other than finding an opportunity to rescue my sister, I also wanted some strong kittens, since he's a dragon and all, but if I hadn't seen him changing a couple of times, I'd be convinced he's a eunuch nya~! He only has eyes for a fight, and it almost gave me a complex about my feminine charms for a bit…" She gently cupped her breasts and gave an exaggerated frown.
"OH! Nate gets like that sometimes when he's on the verge of a breakthrough with his research! It's cute!" She giggled, making Kuroka join in.
We sat in comfortable silence for a moment.
"…since I'm a devil now too, I figured I may as well go all in, since my children will be born as devils no matter what…"
After a moment's thought, I broke the brief silence.
"You know, I've actually got a stray devil in a coma in my lab basement, and I'm only one or two breakthroughs away from curing her…"
Kuroka made a choking sound as her eyes bugged out in surprise.
"If you'd like, once I understand the process, I could maybe…remove your evil pieces for you?"
She pursed her lips and pondered it for a moment before sighing and shaking her head.
"Like it or not, being a devil bishop is a big portion of my strength, if my pieces were removed I'd probably just be a regular mid-class yokai…I wouldn't be able to protect my species any more…but if you could cure my sister, I'd be very happy nya~!" She exclaimed, perking up quite a bit at the end.
I chuckled.
"If you can bring her to me, I'd be happy to! Any idea where she is?"
"Last I checked, she's serving the little sister of the current Satan as her Rook nya~."
Kunou and I look at each other.
"…you might need to temper your expectations a little…"
"Hey, House Gremory tend to be very reasonable people, I'm sure we'll be able to come to an agreement somehow nya~!"
She laughs, then sighs.
"It's just a shame that you can't partially cure someone, not sentencing my children to being devils as a consequence of my power would be fantastic, but sometimes you have to make difficult choices nya~…"
I turn in the direction of the main laboratory, thinking about the devil woman in the basement. CAN I partially cure someone so that their children won't be devils? It would be difficult, but it actually might be possible, and learning how to do that could help make the process less painful too…and my motes seem to agree.
"I…might actually be able to do that…"
She goes quiet.
"I mean, I can't promise anything, but I have a feeling that it may be possible. I'm sorry I couldn't be more helpful, but-"
I'm interrupted by her jumping over the table into my lap and throwing her arms around me, her face buried in my chest.
"WHOA!"
She looks up at me, her big golden eyes damp.
"Y-you think so? You mean my children wouldn't have to be devils!"
She nuzzles her face into my chest again and sniffles loudly. I'm probably going to have to clean this later…
Kunou quickly leaned in to hug her from the side, so I gently returned her hug, rubbing her back a little as she sniffled a few more times before composing herself.
"Apologies for such an embarrassing display in front of the Sage nya~"
I gave her a gentle smile. "It's fine, I understand, it's a lot to take in."
"Thank you, you have…no idea how much this really means to me…"
We sit in silence for a moment before Kunou interrupts.
"This is very moving and all, but could you, uh, get out of my boyfriend's lap?"
Kuroka looks down, noticing that she is, indeed, sitting in my lap.
"I would, but something tells me the two of you don't mind sharing nya~." she said with a grin.
Kunou looks back at her in shock.
"What makes you say that?"
Kuroka looked back at her with a…devilish grin.
"Well, like I said! I've chatted up my share of simpletons to convince them to help me in exchange for a chance to get lucky, so I'm very used to hungry looks nya~!"
"Hey, I've been trying not to stare, but you really are very beautiful and you're right here…"
She scowled exaggeratedly at me, then giggled. "Let me finish nya~! His gaze is hungry, but not curious, and no offense, but I don't think you'd be able to satisfy that curiosity…which means there is another woman nya~!"
"Some taken, but I'm used to how men from the different yokai clans look at me…evaluating me as if they can see how much political power they'll gain, so I suppose you would be able to tell…" She thought for a moment. "We can't say who it is though, top secret stuff!"
She tried to give an apologetic grin and I nodded along. "Very top secret!"
Kuroka looked between the two of us for a moment before gasping out loud.
"Wait, you're ploughing Queen Titties herself?!"
Aaaand Kunou's shocked sputtering gave it away…
"I've gotta ask, how majestic are they in person nya~?" She lowered her robe, showing off her…quite sizable bust, making Kunou sputter even louder. "I know I've got plenty going on, but hers must be next level!"
"Yours are…very nice, but yes, she is…uhh…much larger." I answer as diplomatically as possible and tried to avoid staring at her admittedly…delicious looking nipples.
Kunou finally managed to recover her ability to speak. "Hey! You better keep this quiet!"
"Don't worry, I'll keep this hush hush, just for you nya~." She promised, before entertaining a new sly grin. "That said, I'm sure your man wouldn't do it, but I know you MUST get compared to your mom all the time, what with how much smaller you are."
"Hey! My trainers say I'm 'delightfully sporty' so watch your mouth. Besides, it's not really fair to compare me to a fully grown…fertility goddess like her!"
"You don't look fully grown to me nya~. In fact~, you look like you can barely take what your man here can put out~."
Oh no. She's baiting her…
"And you think you can handle what he can put out?! Nathan!"
I sighed audibly. "…yes dear?"
Kunou bit her lip. "I think we should teach her a lesson!"
"Are you sure?" I asked, Kuroka carefully pretending that she isn't vibrating in my lap.
"Yep! Let's see if this VIRGIN can handle my man!" She exclaimed, visibly blushing and fidgeting. She's not fooling either of us, but Kuroka happily disrobes.
Unlike Kunou, she doesn't hold back from licking me to show her affection.
"I suppose I should strip too?"
"Definitely nya~." Kuroka answers enthusiastically.
When I slipped off my clothes, she gasped a little at the sight, clearly appreciating both my well toned form and my endowment.
She hesitated a moment, breathing in and out before smiling at me a little shyly. "Don't mind if I do nya~."
Kuroka groaned as she slid down onto my dick, her eyes unfocusing and blissing out a bit as she bottomed out.
Kunou leaned in and whispered into her ear. "It's so warm, isn't it?"
"Mhmm…I can feel his heartbeat…" She bit her lip and rubbed her lower abdomen, then her jaw dropped as she felt the barely protruding bulge. "FUCK!"
"Fuck indeed!" I joked, hearing her gasp as I pulled out, then yowl and begin convulsing from overstimulation as I bottomed out again.
…
I may have neglected to consider that my Sex mote gives me hours of 'training' every day, so in the many weeks I've had it, I've gotten more sexual 'experience' than almost anyone alive, and…Kuroka is a virgin who just had every single sensitive spot in her pussy stimulated at the perfect timing to maximize pleasure.
Kunou squeezed her breasts and bit her lip before leaning in and huskily whispered into Kuroka's ear. "Losing your mind already? How's that for taking what my man can put out?"
Kuroka panted for a moment to catch her breath before shooting back. "I-I just needed a second to get used to it, I'm okay now!"
Kunou grinned menacingly, tweaking her nipples through her shirt. "You heard the lady! Don't hold back!"
Taking a moment to dial back my Sex mote from mind breaking levels of pleasure, which I can…apparently do now? Best not to think about it! I resume thrusting into her tight, warm wetness at a relatively vigorous pace, accompanied by a choir of moans and yowls from my very enthusiastic catgirl partner.
Now, I'd normally last much longer than this, but between the very noisy catgirl clenching around me like a vice and my kitsune girlfriend fondling herself and disrobing to give me a show as she whispers insults into said catgirl's ears, it only takes a few minutes to lose my composure, blasting a load infused with Yang Ki directly inside Kuroka, her whole body going rigid, even her tails, in a comical fashion, as I spy in her big, expressive eyes metaphorical supernovas going off.
"WHAT ARE YOU DOING TO ME!?" She yowled with teary eyes.
At least I think that's what she said, it came out more like "WHAGHAGHHEOJME", but her inability to form words is understandable given the circumstances.
Kunou snuggled up against her side and whispered into her ear, "Just relax and feel his divine seed filling you…"
Once our shared orgasm subsided, however, she immediately hunched over into my chest and tried to clamber off of my dick, falling backwards onto the table. "NGH! BURNS!"
As Kuroka grimaced and clutched her lower belly, shivering as her stomach cramped constantly under the pain of the 'pure' energy within her, Kunou leaned over her and gave her a toothy grin, her gaze dripping with arousal. "Seems like the pleasure my man can give is a little too heavenly for a devil like you…have you learned your lesson, yet?"
"I-I apologize! I was too presumptuous in trying to seduce your man nya~! Please help me out here!"
"Aww, humbled so easily? I was hoping you'd be a little more defiant!" Her grin grew even wider. Were her teeth always that sharp?
Compared to this, she was positively loving with her mother. I don't know if I should encourage this or not, but I do know one thing.
I have got the weirdest boner right now.
"Want to know how to absorb the energy contained within the Sage's cum, hmm?" Kunou rubbed Kuroka's lower belly, making her groan.
"Y-yes please!" She nodded vigorously and tried to smile.
"So, this is a technique called Dual Cultivation, and the two of us invented it!" She exclaimed. "Skipping over all the details, you'll need to circulate Yin Ki around your womb-"
Kuroka's loud scream interrupted her, having evidently tried it out before she finished speaking and made the pain worse!
Quickly pivoting, she tried to pretend that she wasn't done giving instructions and came up with something new. "Circulate it AFTER you've channeled some of your Yin Ki directly into the mass of Yang Ki!"
Kuroka groaned loudly and shook her head. "DIDN'T WORK!"
Kunou thought for a moment. "Maybe the concentration is the issue? But how could you dilute it…"
Kuroka groaned skeptically in my general direction after two failed attempts in a row and asked, "Should I try channeling my Demonic Power into it and then circulating Yin Ki?"
I thought for a moment and nodded, Dual Cultivation confirming that should help.
Kuroka breathed in, then moaned loudly and huskily, a very brief and faint flash of some energy I didn't recognize in her core, before it subsided, her quivering muscles relaxing.
Kunou grinned sheepishly. "See, easy!"
Kuroka glanced at her with a raised eyebrow. "What happened to inventing this technique?"
"Hey, we're still working out the kinks!"
I rolled my eyes and cut off the argument before it could get more heated. "Does it still burn?" I asked, a little concern leaking into my voice.
She rubbed her lower abdomen, then looked at my still full mast and bit her lip, her pupils dilated with lust. "A little bit nya~!"
Okay, I think she likes it rough.
And then she hopped up from the table and quickly hilted herself again-!
Kuroka's eyes burned with intensity. "I'm not humble at all! Don't coddle me like some soft mid class yokai!" Kunou bristled at that statement. "Use that Sage body of yours and fuck me through this bench!"
Okay, she DEFINITELY likes it rough.
You know what? This might be fun.
Whatever Kunou was about to do to her is cut short as she was forced to leap back to take cover from the splinters as I actually fucked Kuroka THROUGH the bench, laughing maniacally all the while. Cracks spiderwebbed through the trees that formed the walls as I pounded her against the wall with her legs folded up into a mating press, making Kunou stare in awe as she remembers just how strong I am.
And now I can sense her widening her stance and shoving her hand between her legs.
Once she gets to high class, she's going to make me grow furniture just so I can fuck her through it, isn't she?
Having sex like this is so much more intense, and I can feel myself getting close, my Yang Ki flowing into my balls, and her Yin Ki and Demonic Power flows accelerating as well. I feel a surge of euphoria as I blast a load of Yang Ki into her womb and it begins to mix with her own, her rapturous expression and loud yowling clearly betraying her orgasm even if I couldn't see the supernovas behind her eyes.
And then I realize that Dual Cultivation with a devil forms Demon Ki, just in time to let out a very manly and dignified whimper of agony as said Demon Ki burrows into my body, burning it's way through my meridians and giving me a flashback to that day on the playground when I pulled unfamiliar energy into my body for the first time.
Then I let out an astonished gasp as a faint Demonic Power Manipulation mote glowing with unlight flares to life in my soul.
As Kuroka gasps for breath and Kunou continues panting, I take a moment to inspect the new mote. Sadly, it doesn't seem to be able to grow my reserves, since I…don't actually HAVE Demonic Power reserves. It seems to be connected somehow to the Mana and Merlinean Magic motes? I'll figure it out later.
I carefully turn around and lay Kuroka down on the table, sitting down on it to recover from that…ordeal.
Then Kunou moans, rushing over and slamming her mouth into mine, then breaking the kiss and actually licking me. "PLEASE! I'm so close!" She rests a few of her tails over my shoulders to help lift her up for easier access, and I quickly hilt myself inside her and begin pumping my very sore body for her pleasure as wetness splatters all over my lap.
I channel Yang Ki to my balls, which, despite my current state, accelerates my release almost as much as any contribution Kunou can make. Can I train to manually ejaculate on command? The Sex mote affirms this after a brief mental prod. Neat.
As Kunou and I perform Dual Cultivation, the rush of Life Ki soothes my aching meridians, like coming home from a long trip.
Kunou rests her head against my neck for a moment, then looks up and smiles at me.
"Well, that was fun, wouldn't you agree?"
"Tiring, but I've certainly done more unpleasant things!" I chuckle, then Kunou joins in as Kuroka also groans in agreement, conserving her energy by not speaking.
Kunou leans down and grabs her hand. "How are you feeling now that your brains aren't leaking out your ears?"
Kuroka lets out a strained grunt. "Like a used napkin…"
I feel Kunou's insides clench. She REALLY wants to get worn out like that…
"By the way, I'm not fucking you again unless Kunou is ready to fuck too, getting a share of that Demon Ki shit fucking hurts! I think we might be doing it wrong somehow…"
Kuroka whipped out a Cheshire grin. "Guess we'll just have to practice it then! Good thing she's so easy to jumpstart nya~! I swear, it's like she never learned to control her heats…"
Kunou snickered, then stiffened and glanced towards me, checking to see if I…noticed something…?
"Wait, heats?" I ask, confused.
Kuroka cackled wildly. "Wait, you never told him about heats? Did he think he could just breed you any time nya~?"
"No! He knows I won't get pregnant now, I told him that! I just…didn't want to bring up heats because it's…awkward…" She covered her blushing cheeks, very adorably, and busied herself with getting something to drink from a cabinet on the other side of the room, trying to ignore our discussion.
"Sooo…what am I missing?" I asked Kuroka.
"Long story short, you know how some animals have heats? Well, yokai of similar lineages also have heats nya~."
"Alright, should I be aware of a…mating season…or something like that?" This is a little concerning.
She giggled as if this wasn't a big deal. "Nah, any yokai nearing adulthood is taught how to use Senjutsu to control her heats so she doesn't lose control of herself and attempt to breed with random humans nya~."
"Okay, what does a heat look like then?"
Kuroka sat up and idly played with one of her nipples. "Imagine her blushing and panting and drooling everywhere from both mouths nya~!"
Wait a second.
"Would she do the same thing if she absorbed a lot of purified natural energy?"
Kuroka bit her lip and pinched her nipple a bit while she thought for a moment, then grinned and turned in Kunou's direction.
"Oooh someone wanted her first time to be extra special nya~!"
Kunou whipped around (spilling the glass of water she poured herself) and turned to face us with a positively NUCLEAR blush. "SHUT UP!"
Kuroka snickered. "I can see why you love her so much, she's so CUTE nya~!"
I laughed in agreement, then leaned back down to her. "So she just wanted her first time to be special?"
"Of course nya~! A lot of yokai women swear that having their first time during a heat makes their bond even stronger!"
I looked at the nuclear blush on Kunou's cheeks that she was trying and failing to cover with her hands.
"One thing you can be certain about is her love for you nya~. She probably can't imagine a world without you being by her side any more…so take good care of her nya~!"
After thinking for a moment, I step over to Kunou and remove her hands from her face.
Then I kiss her.
I can feel her crying a little, but she returns my kiss with gusto, and after a few moments, I break the kiss and pull her into a hug, gently swaying back and forth in a quiet dance for a few moments.
"Gee, now I feel like the third wheel!"
Kunou and I both burst out laughing, the jovial atmosphere returned.
"So!" I yelled over to Kuroka. "What do you plan on doing now?"
"For now, I'll stick with Vali's team. I should be able to break from the Khaos Brigade pretty easily, not like something as paradoxical as an international isolationist organization would have much structure to begin with nya~."
"Well, let us know if we can help with anything, and you probably ought to stop by occasionally to help with my research on removing Evil Pieces."
"Can do nya~!" She salutes and lays back down lazily. "I'll leave in a bit, I think a catnap is in order…"
…
Wow, snoring in under 5 seconds. I must have worn her out.
I walked over to her and gently kissed her on her forehead, and heard a…faint rumble coming from her chest? Is she…purring?
Kunou walked over and stared in awe. "That's adorable…we're keeping her!"
I just rolled my eyes. "Shouldn't you inform some contacts back home about her?"
"Yeah, I'll tell mom, and maybe inform Nurarihyon that Fujimai is deceased. I knew I recognized the name, and she used to be part of his faction, and he's been searching for her for a couple of decades now…"
"Yeah, he probably didn't have much hope left at this point, but at least it gives him closure, and he might meet her daughters eventually…" Spotting her ear twitching, I added. "I'm sure he'll be happy that they grew into wonderful young women…"
The tip of one of her tails swayed gently back and forth.