Celestial X Grimoire (DXD Celestial Grimoire)

I finally reached the house, and saw my little sister already there, waiting for me.

"Ryuu-nii, there you are! I've been waiting for hours!" Tomoko said, with an annoyed pout as she looked at me.

"Ah, sorry I'm late… I just had to uh run some errands" I said, as I walked inside and shut the door behind me, "Don't worry, it wasn't much… but it's related to what I wanted to talk to you about. Where are mom and dad?"

"Dad's still at work, and mom went to bed early. Dinner's in the fridge, by the way," She told me, gesturing to the kitchen, "Mom made a really nice soup"

"Ah nice, I'll be sure to have that later," I said with a smile, before looking down at my sister, "Now… let's head up to my room"

"Finally! You've kept me in suspense for way too long" Tomoko said happily, as she ran up the stairs on all fours like the gremlin girl that she was, before I followed her at a more leisurely pace.

Once I got inside, I shut the bedroom door behind me and made sure it was locked, before turning around and… seeing my sister with her clothes off.

"Damn it, Tomoko" I muttered, as I fought my natural reaction to grow hard at the beautiful sight, "P-put your clothes back on. No, bad!"

And of course, when I treated her like some sort of disobedient pet, she just gave me the lewdest look imaginable with a flushed face, before putting her skirt and underwear back on… but noticeably didn't put her shirt back on.

It's not like there was much to look at, to be fair. Her breasts were rather small, even if her nipples were deliciously puffy, and made me just want to suck on- no. Bad thoughts.

Think about pounding my sister later, brain. At this moment I have to focus on revealing magic to her.

"Alright, if you didn't want to fuck like bunnies, what did you want to talk about?" She asked after a moment, looking at me nervously, "You're- you're not gonna say that last night was a one time thing, right? Because after finally seeing the light, I- I don't think I can go back to no hot dickings!"

I saw the look of desperation on her face, and couldn't help but sigh. Of course she'd get nervous over not fucking her brother… but really? Hot dickings?

"No, Tomoko. We're still going to fuck" I said, causing her to 'whoop' in joy as she pumped her fist in the air, "No this is something more important"

"Nothing is more important than sex, Nii-san," She said almost instantly with a little smirk.

Well… now I have to figure out just how I'm going to reveal magic to her.

Now, how the hell am I going to reveal magic to her? Try to explain what I discovered… no, she'd probably call me crazy if I didn't give her hard evidence.

And likely, whatever evidence I do use, she could try and rationalize away as a prank or something along those lines. I didn't think she was a skeptic, but it took me some pretty hard evidence to get convinced.

…Fuck it, what if I just rip off the bandaid and just tell her straight up? That might, that might work. Or at least it'd be a far faster way of doing things, if I suddenly changed her outfit into an entirely different one in less than a second.

"So, uh… are you going to tell me or just stand there thinking?" She asked after a moment, causing me to look back to her.

Ah, I'd been lost in my own thoughts for a second there, oops.

"Magic's real" I blurted out, causing her to quirk an eyebrow. Ah damn it, why did I have to say it like that?

Of course, she wouldn't believe me, especially when I just blurt it out.

"Really? Are you just screwing with me, Ryuu-nii?" Tomoko asked, an unimpressed look on her face.

Yeah, she didn't believe me, so I quickly summoned a Costume Switch tag, and placed it directly onto her forehead.

"Huh? What's this?" She asked, before her school uniform glowed for a brief moment, and she was now standing in… a magical girl outfit.

Instead of the Kuoh School Uniform, she was now wearing a red and black dress with golden accents, a small frilly skirt that showed off her smooth legs, and two red bows in her hair, there was also a large broach with a gemstone in the shape of a heart sitting directly on her chest.

She honestly looked like a pure and adorable magical girl, who would go out and save the day in the name of justice… even if her eye bags hinted towards her true NEET nature.

"What the fuck!?" She screeched, as she looked at the outfit she was wearing, before looking back at me, "What the fuck!?"

Yeah, that image of her being a pure and adorable magical girl was kind of ruined.

"I mean, I told you. Magic's real" I said with a small laugh, before she leaped over to me, toppling me over as she stared into my eyes with a manic expression.

"How!? Why!? When!?" She demanded, eyes widening as she practically throttled me. But it wasn't like it hurt or anything, she wasn't strong enough to do that.

"Uh, magic… magic, and a couple days ago," I told her with a little grin, causing her to pound against my chest.

"I- you!… Holy shit, magic's real" She muttered to herself in realization, a look of wonder making its way to her face.

"Yeah, it's cool, right?" I said happily, causing her to just stare at me, "I mean… I only discovered this a couple days ago. But there's so much awesome shit out there! I mean, there's also the horrors but we don't talk about that"

"The… the horrors?" She asked, a disturbed look on her face.

"Right, I'll catch you up to speed. So uh basically, our town is run by demons… Devils, whatever. Don't know who they are, but they apparently like to enslave people, turning them into Devils.

This is from a pretty biased source, which while I do somewhat trust… well I haven't met a Devil, so I don't know what they're like" I said, rambling a little bit at the end there, but getting the general point across.

"Devils? Like… The Devil. From the Bible?" She asked, causing me to nod, "…Does that mean God's real? What about the Kami's? What about Oni? What are the implications here… wait! Are catgirls real?"

She looked at me with such desperation for that last question, that I couldn't help but chuckle.

"Uh, yes. Apparently, God does exist, the Kami's are real, same with the Oni… and I think catgirls are real too, I mean if Kitsune are, then they should be, right?" I told her with a shrug, causing my sister to let out a little squeal of excitement.

"Oh shit, oh shit… catgirls are real… and so are foxgirls. Oh, I have a lot I want to do with that information," Tomoko told me with a perverted look on her face, which clashed quite a bit with her magical girl outfit.

…Damn it, Tomoko. Can you stop being a degenerate for one damn second? I'm trying to tell her some really important shit, and now her mind's filled with a catgirl and foxgirl harem.

"Wait, you- you have magic right, nii-san? What's it like?… How do I learn magic?" She asked a look of heavy interest on her face, after she eventually snapped out of her imagination fueled

haze.

"Well you need to use a lot of calculations… or in my case? Cheat" I said with a grin, as I fired a small Zap at the door.

A glowing yellow bubble flew out of my hand, and impacted against the door, leaving a small burn mark on it.

"…I want that," She said as she stared at where the door was burnt.

"Well uh, maybe I could teach you in the future," I said, not wanting to get her hopes up, I didn't exactly think I could do that sort of thing.

The Celestial Grimoire was weird like that. Maybe I'd learn something that could help me teach my abilities to other people, but I wasn't sure about that.

"Ah damn…" She muttered, a downcast look on her face, something I hated to see, even as she was still on top of me.

"I mean, I could enchant an item with the spell," I said quickly, causing her to look at me with a renewed sense of hope, "But it'd be powered by your own magic, and if you don't have enough magical reserves? Well, I can't really do anything about that"

"Don't worry nii-chan, I'm a magical girl now… of course, I'll have magic!" Tomoko told me with an excited grin, as she twirled around in her new outfit.

"Heh, alright. I'll try to make you a wand or something later on" I said, causing her to let out a cheer.

Well I probably wouldn't make her one, I had no idea where to start with that… but I could probably buy one from some sort of store, maybe say it's for a cosplay or something?

That should work just as well, right? Or would I need to specifically make something and place the magic into it during the crafting process?

The magic didn't really say anything about it, so I shouldn't have to do that sort of thing, at least… that's what I think, but hey... I could be wrong.

I hadn't really used it, after all. So I had no idea how this sort of thing actually really worked.

"Thank you nii-chan! You won't regret this!" Tomoko said with a happy little grin, as she started to grind herself against my knee, with a flushed look on her face, "In fact, I think you deserve a little… reward~"

The magical girl outfit that I put on her offered no resistance, as I noticed a pair of damp red panties around her core, slowly getting rubbed against me.

I looked at her for a moment, before remembering what she did to me during lunch, so I quickly decided to turn it around on her.

By literally rolling my body so now I was on top of her, as she looked up at me with shock… before her expression shifted.

"Oh? What are you going to do, nii-chan? Are you going to… ravage me?" She asked with a taunting grin, a slight haze in her eyes.

"Hmm…" I hummed as I looked down at her, trying to figure out just what sort of punishment I should give her.

She was a very naughty girl today, after all.

Staring down at Tomoko, I couldn't help but smile when an idea occurred to me…

"Wait right here," I told her, as I slowly got off of my sister, causing her to look at me in confusion.

"Wait- aren't you gonna punish me?" She asked, sitting up and staring at my retreating form.

"Oh, you'll be punished alright. But just spanking you isn't going to cut it" I said, as I closed the door behind me, and walked over to Tomoko's room.

Her door wasn't locked, an amateur mistake, so I went inside and started to look for some of her… toys.

I eventually found quite a few of them hidden in her bottom drawer, and discovered that underneath her bed, was a massive pile of hentai doujins.

Peering into the drawer, I saw dildos and vibrators of various shapes and sizes, and I even found a couple of little egg vibrators along with a controller tucked away in the corner.

I pocketed the egg vibrators to use at a later date, and grabbed one of the vibrators. It was a decent sized one, around six inches long with a vibrating ball at the tip.

There was also a way to adjust it on the device itself, and looking at the battery compartment, I found that there were already two inside.

Making sure that it worked, I turned it on and heard a light hum as the ball vibrated. Yes, this would work.

So I made sure to hide it underneath my shirt, just in case either of my parents saw me walking out of Tomoko's room, and went back into my room, where I saw my sister sitting on my bed.

"You're back? What did you get?" She asked, as she looked over to me.

"Take off your skirt," I told her, causing her eyes to widen and a lewd look to make its way to her face, as she swiftly dropped both her skirt and panties.

I glanced down to the panties, to see that they were already absolutely soaked, her girlcum visible from either side.

"So what are we gonna do? You gonna fuck my ass? Turn me into your mewling little bitch dog? Make me guzzle down your spunk? Shove my face into your nutsack and make me addicted to your scent!?" She asked with a frantic fervor, as she spread her legs for me, exposing her pink slit just barely hidden by her pubic hair.

"Bad girl. I said to drop your skirt, not your panties," I told her with a stern tone, as I slipped the wet panties back onto her, "You definitely deserve this punishment"

Her eyes widened a bit, as I took the vibrator out from under my shirt, before her lips quivered and she gave me a salacious little smirk.

"Oh no~ What are you gonna do to me?" She asked, spreading her now panty clad legs, the small mound just barely seen underneath her red underwear.

I marched over to her, before turning the vibrator on at the lowest setting, a slight hum coming out of it as the ball shook.

Then I placed it onto the small mound just barely hidden by her panties, smiling as Tomoko moaned lightly.

"Ah… oh, this feels different from when I do it" She mumbled with a small blush, as I looked into her eyes.

"Well, of course it would, you're not in control of the movements," I told her, before finding a small nub and placing the vibrator onto it, before putting it on the next setting.

Tomoko gasped, her pupils dilating in arousal as I teased her clit, the vibrator on the second lowest setting, but even that was enough to work on my sister.

She looked into my eyes with such love, adoration, and devotion that it just made what my punishment was going to be… all the sweeter. Huh, I might have had a little bit of a sadistic side to me. Who knew?

I watched as her legs started to shake, and I just knew that she was on the verge of orgasming… so right as she was on the very edge, I pulled the vibrator away.

"Wha- I- wha? Huh? Where… where'd it go?" She asked breathlessly, her eyes losing their lucidity as she looked up at me.

"What part of punishment don't you get, Tomoko-chan?" I asked with a kind smile, as I waited for her to come back to her senses, my sister's body slowly returning to its norm, as the sheer need to cum eventually went away.

"No… no…" She looked at me with horror, as I slowly moved her panties to the side, exposing her hairy little pussy, absolutely caked in her own juices, it was a tantalizing sight, but I couldn't just dive right into her awaiting snatch, "Y-you wouldn't do this- nii-chan! N-no..."

This was her punishment, after all. And some spontaneous cunnilingus would be a reward… and her actions aren't to be rewarded.

"This is your punishment, my dear, I'm sorry but maybe you shouldn't have teased me so much~" I said with a small smile, as the vibrator in my hand hummed to life once more.

And so, I continued on into the night, gently teasing my sister as she moaned lightly, just about to cum… and then took the vibrator away.

She tried to finger herself to completion once, but I just held her hands and legs to stop her from doing so.

Tomoko still wore the top half of her magical girl outfit, even as it was slick with sweat, her hair and little bows similarly gaining a slight wet sheen to it.

"Phlease… please… jus' lemme cum" My sister begged pathetically, mewling with every slight movement I made.

Looking at the clock, I saw that it had been four hours since the two of us started, and she was looking a little worse for wear.

"Nii-chan please… I'm sorry, I- I'm so sorry! Please please please lemme cum!" She moaned out, as I inserted one of my fingers into her needy pussy, the first bit of penetration she'd gotten all night, and of course, Tomoko started to buck her hips, in an attempt to steal an orgasm from me.

"I'm sorry but I can't do that, Tomoko" I told her, as I put in a second finger, making a circling movement as I pistoned my digits in and out of her gushing pussy.

But I knew that this wasn't her cum, no… this was just her natural juices trying to lubricate me so she could cum. So I kept going, the bedsheets growing more and more wet as I got to the point where she really tried to buckle her hips.

And then I stopped once more, before taking my fingers out and putting them into my sister's mouth. She needed to clean me off, after all.

"Nii- I- please... mmnf!" She moaned into my hand, her tongue swirling around my fingers as she looked at me with a desperate plea.

I ignored her pleas though, and decided to continue this into the night, making sure to continue edging her until I figured it was around time to go to sleep.

So with that, I decided to give her a final little reward for being such a good girl all night long.

I put my fingers back into her, and started to go fucking crazy, flicking my fingers inside of her love canal, until she was just on the verge… and kept going.

"Nii- I'm- I'm please- lemme cuuum~" My sister groaned into my shoulder, as I finally allowed her to cum, a torrent of her juices squirting out of her, as she buckled her hips, trying to ride out the high of her orgasm for as long as possible.

Deciding to time it, I continued to finger her, and by the time she was done? She'd been cumming for a good three minutes… and she looked like she was in complete and utter bliss.

And during this, I was fairly sure that I saw something red on her right arm, but it vanished as quickly as I noticed it. Huh, what was that about?

"Aaah… that was… holy shit…" Tomoko said, at a loss for words as she lay beside me, cradling me like when the two of us were children, though without her pants or underwear… it was certainly a lot more lewd.

"What did you think?" I asked with a little smirk, causing her to stare at me.

"That- that was fucking amazing. Never do that again," She said, looking at me intensely, "The ending was so good but it took… so long… I need… sleep"

Then she closed her eyes, and started to snore into my chest, falling asleep nearly instantly.

I just kissed her on the forehead with a smile, and fell asleep beside her. I may not have gotten to finish myself, but… that was fine.

We could just do something more satisfying tomorrow.

_________

Happy New Years everybody!