My Dress Up Monster Girls

WARNING THIS STORY CONTAINS: Marin and Sajuna (My Dress Up Darling) Transforming into Rachnera the Arachne and Centorea the Centaur (Monster Musume)

For the sake of a unique cosplay shoot, Sajuna and Marin take a pair of pills that turn them into monstrous forms that perfectly copy Centorea and Rachnera from Monster Musume.

This was a commission for transformationguy365 on DA: https://www.deviantart.com/transformationguy365

Commission Info: https://www.deviantart.com/eyebeast/journal/Commission-Info-615442807

---------------------------------------------------------------------------------------

   Sajuna stood in front of the door, rapidly tapping her foot as she waited for Marin to let her into the apartment. She tried to keep herself occupied by fidgeting with her pink hair and ensuring her cyan blouse was free of wrinkles. However, her impatience only grew upon pulling out her phone to see that her friend was half an hour late for their appointed time. Thinking that maybe she had gotten the date wrong, she turned to leave only to stop as she saw someone running up to her.

   Upon seeing the woman’s long blonde hair and painted pink nails, Sajuna immediately recognized her as Marin. Coming to a screeching halt moments before colliding with her, M­arin hunched over to place her hands on her pleated skirt and catch her breath. Recovering from her rapid sprint, she stood up straight and brushed off cake crumbs clinging to her white, button down shirt and navy blue tie. Towering over Sajuna by about a head, she had to lean down to show off a wide grin.

   “Sorry I was late,” Marin said.

   Sajuna gave her a deadpan stare. “To your own apartment?”

   “Yeah, things got a little busy after class,” Marin replied. “I’m super hard at work getting ready for finals. They’re really hitting the seniors hard this year for some reason. I’ve barely had time to catch up on all the eroge games I got from my 18th birthday shopping spree. Then I met up with Gojo for some cosplay supplies and a quick bite to eat. Not to mention the traffic I ran into at the-“

   Marin was silenced as Sajuna held up her hand. “It’s fine. You’re here now, that’s what matters. Now can you tell me about this ‘special’ cosplay shoot you had in mind? You know how far away my university is from here.”

   Marin smiled. “It’s a surprise.” Puffing out her chest, she opened up the door and gestured for Sajuna to follow her inside.

   With a shrug of her shoulders, Sajuna entered Marin’s apartment. Making her way to Marin’s room, she once more found herself surrounded by walls absolutely covered in posters for various games, anime, and manga. While there were a few new additions since the last time, the one she centered her view on was the large print hanging above Marin’s TV.

   The image depicted a cast of various monster girls, each one more exotic than the last. Sajuna recognized each of the curvaceous women, having spent a good bit of time both reading the manga and watching the anime they came from. Though each of the Monster Musume girls were attractive in their own way, she couldn’t help herself from focusing on Centorea the centaur. Gazing at the horse woman’s pointed ears, blonde hair, and busty bosom, she once more felt a longing in her chest that made her want to be like her. Having to tell herself yet again that it was an impossible cosplay for several reasons, she turned around to see Marin staring at the same poster.

   “It’s awesome, isn’t it?” Marin asked. “Bought it just the other day in celebration for our cosplay shoot.”

   “Ah, so that’s what you want to do,” Sajuna commented. “Should make for a pretty interesting series of pictures. So who did you have in mind for us? I could probably do Papi since I’m small enough and have some leftover feathers from an angel cosplay. I’m sure with enough materials for the tail and a borrowed wheelchair you could make a good Mero. Or maybe we could look into one of the M.O.N. girls.”

   Marin shook her head. “I have the perfect pair in mind.” Stepping up to the poster, she slammed her hand against the multi-eyed face of the spider woman. “I want to be Rachnera the arachne.” Ignoring Sajuna’s skeptical look, she once more slapped her hand against the poster to bring attention to the very monster girl Sajuna had been staring at moments earlier. “And I want you to join me as Centorea the centaur.”

   Sajuna let out an exhausted sigh. “As much as I would like to do such a unique cosplay, it’s a little above our skillset. The sheer man hours needed to make the props would be staggering, let alone trying to make them look anything like the real thing. Not to mention…I’m not exactly built for Centorea’s proportions.”

   Undeterred by Sajuna’s words, Marin rushed over to her purse. After a few minutes of rummaging around, she pulled out a baggie with a collection of various colored pills. Sifting through the collection, she eventually pulled out two of them, one purple, the other a shimmering gold.

   “That’s why I have these,” Marin said, handing the gold pill over to Sajuna.

   “What are these exactly?” Sajuna asked, holding the pill up to the light.

   “They’re supposed to be drugs to help us with any monster girl cosplay woes,” Marin answered.

   “And you really believe that?”

   “Of course,” Marin said, bouncing the purple pill around in her hand. “I got them directly from a person from the manga’s marketing department. They saw our cosplay work and wanted to let us be the first to try these out.”

   “You seriously believed them?” Sajuna asked. “For all we know, they could have just been a shady drug dealer putting on a show to get rid of some illegal goods. What we should do is bring this stuff to the police for-“

   Sajuna was left silent as she watched Marin down her pill without a second thought.

   “Are you completely insane?” Sajuna asked.

   “No, just really eager to do this cosplay.” Walking up to Sajuna, Marin cupped her hands around hers and lifted the pill up to her lips. “Hurry up and take yours. I want to get started with the shoot as soon as possible.”

   All logical thought told Sajuna to toss away the pill and make a run for the exit. However, she found it hard to argue when faced with Marin’s expectant gaze. Knowing full well that she was probably going to regret it, she closed her eyes and swallowed her pill. Feeling the mystery drug tumble down her throat, she opened her eyes and waited.

   “What exactly is supposed to happen?” Sajuna asked as she held out her hands, half-expected them to glow or become covered in red polka dots.

   “Hmm, dunno,” Marin replied, staring at her limbs with similar interest. “Might have just been a sugar pill meant to put us in the right mindset.”

   Sajuna let out a huff. “Then this was a complete waste of time.”

   “I wouldn’t say that,” Marin replied with a grin. “We can still try out the costumes Gojo made for us. I think I left them somewhere around-“

   Marin’s smile faltered as she clutched her skull like she was suffering from a massive headache. More than a little concerned of what Marin’s rash decision had thrown her into, Sajuna began to approach with the intention of rushing her friend to the hospital. She was forced to stop as she watched Marin’s blonde hair rapidly change into a blinding shade of lavender. Concentrating on the sudden shift in coloring, it took her a few moments to notice that the locks were receding until they reached no further than Marin’s neck.

   “Are you feeling alright?” Sajuna asked, recoiling as Marin lifted up her head.

   Sajuna felt her body go numb as she stared at the glossy eyes upon Marin’s face. The pupilless orbs were covered in a shade of crimson red that seemed to stare right into Sajuna’s soul to grasp at her fear. Her condition worsening upon seeing that Marin played host to six of the bug-like eyes, it took sharp a pain on the sides of her head to get her to turn away.

   Grasping at her cranium, she was momentarily blinded as her own hair extended past her hips. Sliding the tips of the elongated strands against the floor, she watched as the pink coloring shifted into a shade of golden blonde. The more she stared at her curtain-like hair in an attempt to figure out what was going on, she eventually realized that something was making it twitch. Recalling the pain emanating from the sides of her scalp, she reached out and felt a pair of pointed ears covered in a thin layer of brown fur.

   “Oh my god, it worked!” Marin shouted, baring her sharpened teeth in a wide smile as she went back and forth between admiring her reflection in the mirror and staring at the sky blue tone that had taken over Sajuna’s eyes.

   “What are you talking about?” Sajuna asked, grabbing a hair tie from Marin’s desk to tame her Rapunzel-like locks.

   “The pills,” Marin replied, putting her six eyes within mere inches of Sajuna’s face. “We’re actually transforming into Rachnera and Centorea.”

   Sajuna gave a light push against Marin’s chest to get her to step back. “That or we’re hallucinating from whatever toxins were in those pills,” she said, managing to put her hair into a very long ponytail. “There’s no way this is real.”

   “It has to be. How else would you explain-“

   Marin faltered once more as her fingers clutched her chest. Thinking maybe she had pushed against her friend a little too hard, Sajuna took another step forward only to retreat as her vision was momentarily blinded by shreds of fabric. Watching the remains of Marin’s top fall to the floor, Sajuna looked back up and gawked at the sight of the pair of engorging breasts struggling to break free of Marin’s bra. With a loud pop, the swollen mammaries tore apart the undergarment to reveal their perky nipples. Momentarily put in a trance by the sight of Marin’s boobs swaying back and forth to revel in their newfound freedom, Sajuna still wanted to believe that there was some rational explanation for all of this.

   Logical thinking went out the window the moment Sajuna felt a sudden tightness in her own chest. Grasping at her flat bosom, she let out a yelp as she felt the bra underneath become strained by her budding breasts. Her hands seemed to move on their own accord to grasp at her boobs as they ripped apart her blouse to reveal her newly gained cleavage. Though her bra was torn asunder mere seconds later, she barely flinched from sheer shock. Brushing away the remnants of her top and undergarments, she let her fingers grope and squeeze the massive tits that looked all too familiar to the centaur woman Marin claimed she was changing into.

   “Wow, I think they’re bigger than mine,” Marin said, casually bouncing her breasts against her palms to compare them to Sajuna’s.

   “This isn’t possible,” Sajuna said, letting go of her bosom and watching her boobs jiggle up and down.

   A sound akin to grease crackling in a pan finally tore Sajuna’s gaze away from her udder-like breasts. Though the sight of black chitin appearing along Marin’s forearms was a textbook example of frightening, Marin didn’t seem to be worried. In fact, she was more than happy to express her excitement with a toothy grin as she looked over her clawed fingers. Continuing to stare at Marin admiring her insect-like arms, Sajuna barely noticed the fact that at some point she had gained enough height to be a full head above Marin.

   Sajuna didn’t have time to explore her Amazonian-like stature as she watched the same black material appear along Marin’s legs. Sliding her fingers along her thighs helped Marin to deal with the strange sensation of her lower body continued to morph. Her buttocks shifted upwards to make way for a large, oblong protrusion that grew out behind her. The misshaped mass was given some stability as it was covered in more carapace. Moments before Marin’s newly grown abdomen sent her slamming to the ground, the emergence of eight extra legs along the growth kept her stable.

   Sticking the ends of the spider-limbs into the carpet, Marin wobbled back and forth to balance herself. Though there were a few near misses, the additional appendages did wonders of letting her get used to her new body. Daring to stand up straight, she was more than happy to gaze upon herself in the mirror and revel in her new identity as an actual arachne.

   The sight of Marin marveling over the white, skull-like marking along her abdomen nearly made Sajuna forget what was happening to her own body. She was given a stark reminder as she felt her lower half burst apart what remained of her outfit. Shuddering as her rear began to extend outwards, she paused at the sound of a loud clop echoing through the room. Having to push back her breasts to get a proper view, she saw more of the thin brown fur spread across her thighs and down her legs to end at the hooves that had replaced her feet.

   Sajuna heard something akin to a one woman stampede as another pair of clopping noises came from behind her. Looking over her shoulder, she gazed at the quadrupedal body of a horse that had taken the place of her lower half. Though the added heft was felt with each step, it was given a sense of balance by an extra pair of legs positioned towards the back. Trotting around on her hooved feet swayed about the tail of blonde hair nestled above her new rear. Upon feeling the strands dangle across a set of private areas, she cautiously looked towards her groin to confirm that more than a few things had gotten moved around during her transformation into a full-fledged centaur.

   “Mmmmm, you look absolutely wonderful.”

   Sajuna swiveled her head back and forth but saw no sign of Marin. Upon hearing something skittering above her, she tilted up her neck to see that the spider woman had nestled herself in a corner of the ceiling. As she used her perch to survey Sajuna’s body and reactions, Marin let her claw-like hands pull and twist at lines of spider thread that came from her newly gained spinneret.

   “How are you doing that?” Sajuna asked.

   “Dunno, just kind of feels right,” Marin replied as she effortlessly tied together a web between her fingers. “Should let us put the camera higher up to get some unique shots.”

   Sajuna unconsciously pressed her arms against her bare chest and let her tail obscure her backside. “Not when I’m like this,” she said, her words being fueled by an innate instinct to preserve her honor. “It would be so undignified for someone like myself.”

   “Wow, you’re really into character,” Marin said as she crawled back onto the floor. “No worries, I didn’t intend to make it that kind of shoot. Sit tight right there.”

   Carefully maneuvering her body through her room, Marin opened up her closet and pulled out a box. Lifting off the cover, she reached in to grab bundles of fabric. Spreading the cloth out on her bed, she stepped back and held out her arms to show off the near perfect recreations of Centorea and Rachnera’s outfits.

   “When did you get these?” Sajuna asked as she stepped up to inspect the costumes.

   “Gojo managed to finish them just yesterday,” Marin replied, puffing out her chest with pride. “He was able to guess at the sizes and everything just from looking at the reference images and using the notes sent to us by the staff.” Carefully grasping the clothes between her claws, Marin held them up to Sajuna’s face. “Come on let’s try them out and snap some pictures.”

   Sajuna let out a sigh. “Very well. Might as well make the most out of this strange situation.”

   Though it was a struggle with their new bodies, the two monster girls managed to get themselves dressed up. Stepping in front of the mirror, Sajuna still couldn’t believe what she saw. Sure, the sleeveless white top was a little tight and gave an unflattering outline of her nipples, but she couldn’t deny that it was accurate to the character. A similar story was told by the tablecloth-like black skirt that covered up her private areas and mostly obscured her horse-like body. Too busy fiddling with her the string around her neck and the hem of her skirt, it took her a while to notice Marin was right behind her.

   “It looks absolutely perfect,” Marin said, hugging her chest at the risk of her breasts popping free of the boob window of her very revealing top. Paying little mind to the danger of snapping apart the silk garment, she proceeded to let her claws graze the lace adorning the tightly fit attire. “Gojo really outdid himself this time. I’ll have to snap some ‘special’ pictures for him later as a reward.” Turning herself around, she reached back to fondle the gold colored loin cloth that covered her groin but left most of her buttocks on display.

   Hearing Marin go silent as she continued to appreciate Gojo’s handiwork, Sajuna got her attention with a stomp of her foreleg. “Are you ready for the photo shoot?”

   Marin blinked a few times, as if she was breaking out of a trance. “Whoops, my bad. Everything just feels so nice in this body.” Grabbing the camera off of her desk, she climbed up onto the ceiling and aimed at Sajuna. “Okay, now give me your best pose. Like a knight ready to protect their beloved from certain doom.”

   The usual confidence Sajuna showed off during her cosplay shoots took a while to come out. Whether it was the unfamiliar body or a strange sense of shame that seemed to be ingrained in her blood, she inevitably got over it after Marin showed off the first few pictures. Swapping places with one another, the girls took turns snapping pictures of their monstrous figures in poses and situations that mimicked the ones they had seen in the manga. Finishing off the session with a timed picture featuring the two of them, Sajuna finally allowed herself to smile upon seeing the life-like image of Centorea and Rachnera in her hands.

   “Wow, that came out really good,” Marin said, looking over Sajuna’s shoulder. “It’s eerie how much we look like the actual characters.”

   “Understandable considering what we’ve become,” Sajuna said gesturing towards their inhuman legs. “That being the case, do you have a way to change us back? I don’t think either of us can fit out the door like this.”

   Marin scratched her head. “Er, I think so. I can’t remember if it just wears off on its own or if we need to take another set of pills to reverse the process.”

   “Marin!” Sajuna shouted, stomping her hooves in frustration.

   “It’s fine, it’s fine,” Marin said, putting the camera aside as she fiddled with her silk. “I’ll call up the PR representative in a bit. AFTER we do one more series of pictures.”

   Sajuna let out a sigh and crossed her arms. “What did you have in mind?”

   Turning back around, Marin brandished a malicious smirk as she stretched out a web that looked similar to bondage gear. “Let’s try out a few more ‘interesting’ poses.”

   Before Sajuna could even think to reject her, Marin moved with astounding speed to tie her up in silk. Hoisted several feet in the air by the spider web, Sajuna’s mouth became muffled as Marin tied silk across her face. Only able to let out a muffled series of grunts for Marin’s rashness, she fell silent as Marin held up her camera.

   Drooping her ears in acceptance of her fate, Sajuna tried to put on a fitting expression to ensure the finale of their photo shoot would be as authentic as possible. With each awkward position and picture snapped, she felt her body grow warm with a strange sense of pleasure from the act. During the moments where Sajuna had to be adjusted, Marin was all too eager to let her fingers explore every inch of her body. Face growing red with a rising sense of wanting, Sajuna would inevitably call out for Marin to take care of certain needs. After all, it would be a once in a lifetime chance to experience such a thing with their monstrous forms.