“This had better be a really good surprise.” grumbled a perpetually scowling Inui Sajuna, better known by her cosplayer name of Juju, currently looking up with her arms crossed at Kitagawa Marin, who was shooting off excitement like sparks. Her aura was a natural repellent to somebody like Sajuna, and being in her room meant she was drenched in that atmosphere. Even worse, Marin was wearing the loudest leopard-print sleeveless top she’d ever seen on top of some loose-fitting shorts, not that they didn’t show off her curvy hips like everything else she owned.

“It is, it is!” Marin bubbled. “It’s totes the best surprise you’ll see all week, no, all month! Maybe even more than that!”

“If it’s so great, then get off your phone and show me.” Sajuna’s eyes flickered to the door as if to send a warning. Marin, chipper as always, was largely oblivious to her moodiness and lack of patience, and only found her more adorable the more she pouted.

“I’m just about to, I’m just getting it ready!” Marin acknowledged that she probably should have had it lined up before she arrived, but had gotten distracted, giving Sajuna ample time to complain.

 “And I swear, if you made me come all this way just to show me some video you found on Instagram.” Sajuna’s brow furrowed.

“It’s not!” Marin quietly shelved the video she had planned to show her a little later after her totally awesome surprise. “It’s just on the phone! Well, it’s not, but it involves the phone, and… Oh, whatever! Juju, you know Interspecies Reviewers, right?



“I don’t!” Sajuna almost squealed back in an instant. “A-a-and I don’t watch lewd anime like that anyway!”

“Oh, so you do know it!” Marin grinned as Sajuna’s face went beet-red. “So anyway, I was thinking of my next cosplay, and in it there’s these cowgirls, and they’re totes cute, and- actually, let me just show you-”

“I don’t want to see it!” Sajuna attempted to flee, but couldn’t escape being flashed a picture of two classic cowgirls with boobs bigger than their heads, to put it lightly.

“See? See?” Marin grabbed her and forced her to look at it some more until Sajuna was outright covering her eyes. “So anyway, I’m gonna cosplay as the one on the right!”

“I don’t care!” Sajuna broke free, scurrying defensively into the corner. Entering the abode of an ecchi fiend like Marin had been a mistake! “Why do you want to show me of all people, anyway?”

“That’s the surprise!” Marin said proudly.

“Well, good luck with that. I am never coming to your place again after this.” Sajuna sighed, regaining her composure. “I’m surprised, actually. I thought you and Gojou liked accurate cosplays, at least as much as you can manage in 3D. Even a cow like you can’t pull off proportions like that, not without some crazy prosthetics. Way more than even Gojou can make.”

“I knew you’d notice, Juju! I expect nothing less from an expert like you!” Marin applauded her. “And that’s today’s surprise! I’m gonna show you just how I’m gonna do it without any of that stuff!”

“Huh?” Sajuna was even more confused. “What do you mEEAAN!?”



Sajuna shrieked as Marin lifted her top before she could react, flashing her with her bare breasts.

“As you can see, there are no hidden devices or equipment!” Marin said shamelessly. Sajuna couldn’t even begin to wonder why this was necessary. “I’ll show you the real trick I have up my sleeve!”

Marin produced her phone, played with it for a moment, then made one last dramatic tap. She carefully set her phone down then stood with her chest puffed up and her hands on her hips. Sajuna felt like something was supposed to happen, and found herself holding her breath. She had been utterly confused from the second she walked in and that hadn’t changed so far, yet Marin had so much confidence she couldn’t bring herself to leave before she saw whatever trick she had planned.

“Is something supposed to be happening?” Sajuna asked when she ran out of breath. The tiny girl looked up at the busty gyaru, her chest once again dominating her viewpoint. “All I can see is your b-”

Sajuna stopped cold, catching herself as she stared at Marin’s huge top-straining chest. It was always one of her biggest features, but now it seemed like it wasn’t just Sajuna’s complex making them look twice as big as usual. She could see the shirt being pushed out, clearly too small, and her nipples poking through the gaudy fabric. Now that it had caught her attention, Marin’s hips seemed curvier too, her loose shorts now seriously filled out by her thighs. Marin looked downright smug at her catching on, and Sajuna’s eyes drifted from Marin’s just slightly off to the side.

“Kitagawa…” Sajuna said slowly, her throat going dry. “Were your ears always like that?”

“Like what?” Marin asked innocently, barely holding back a giggle. They were longer, a different shape, almost slightly floppy. Almost… cow-shaped? Sajuna stared at them, certain that she hadn’t been wearing fake ears a minute ago, nor had she used any sort of trick like covering them with her hair. Somehow, her ears had changed while she wasn’t looking, no, they were still changing before her eyes! The ears finished growing, stuck out to the side, and now that Sajuna was looking for minute differences, she instantly spotted the top of her head. Something was poking through her dyed blonde hair…

“Are those horns?” Sajuna gasped.

“Ooh, are they here already?” Marin started poking them as white, slightly curved cow-like horns finished ascending, sticking up several inches on top of her head. Sajuna impulsively rushed over to Marin, reaching up to grab them herself. Instead of being pulled loose and exposing a headband they stuck firm, feeling just like real horns, instead of the plastic she expected.

“Ow! That hurts!” Marin yelped, then yelped again when Sajuna started tugging on her floppy ears as well. Sajuna was searching desperately for a seam line, proof that she had slipped on fake ears somehow while she wasn’t looking, but found none. Sajuna had cosplayed an elf princess once before, and knew just what a cleverly made pair of false ears looked and felt like. These ones felt practically real!

Before she could demand to know what was going on, Sajuna’s field of vision went dark and her face was buffeted by something ever so soft and pillowy. Marin’s chest had been growing the whole time, and with a sudden growth spurt it practically slapped Sajuna in the face. She pulled herself free with a gasp, eyes bulging out of her head as she stared into a pair of colossal tits bigger than said head, and advancing on her rapidly. She backed away in fear as the fabric threatened to tear, and all Sajuna could think was how soft they were, just like her sister’s hugs but more. Her brain overloading, she grabbed them without thinking, groping them and searching for the trick. Some hidden balloon, or something!

“Hey, Juju, quit it! That tickles!” Marin giggled uncontrollably as she reached her sides. “Actually, you can keep going if you want, these are getting really heavy and- ow!”

“S-sorry!” Sajuna babbled out and backed off, worrying she had jabbed her somewhere.

“No, it’s not your fault, I just need to…” Marin grabbed her shorts and wiggled her hips back and forth. “There we go!”

A full-length cow’s tail popped free of the shorts, wagging back and forth in a pattern too natural to be faked. Sajuna could even see where it sprouted from her skin, with how far up her shirt was pushed by her colossal cowtits.

“Okay, I think it’s done!” Marin declared, her mighty chest heaving as it reached the size of almost two of her heads put together, legitimate beach-ball sized.



“Tadah!” Marin stood with her plumped up thighs and oversized chest before the stunned and reeling Sajuna. “I became a real, genuine cowgirl!”

Marin made the mistake of puffing out her chest a little too much, her top giving up the ghost. With a loud and visceral tear her chest burst free, flopping down with huge, puffy nipples emphasising its scale. This was the last straw for Sajuna, whose eyes rolled back in her head, and the last thing she saw was the cowtitted Marin rushing to catch her, milky droplets flung from her nipples, leaking from the excitement…

—

“I still can’t believe it. A transformation app? Really?” Sajuna said on the side of Marin’s bed sipping on some tea Marin had made for her while she brought her up to speed. She looked down at the milky drink, and didn’t want to ask any details about it.“That’s such a doujin cliche! N-not that I read any of those!”

“It is, isn’t it? I’m not complaining.” Marin agreed, giggling cheerfully as she did up the thin strap that was just enough to cover her nipples. “Okay, I think I got it! What do you think? I’ll admit that I picked this character ‘cause their outfit was easy and fit the cowgirl this thing turns me into, but it does look good, doesn’t it?”



Marin turned around, wearing a brown wig, pink leopard-print pants, and a thin white strap with a large ring in the middle as an alternative to a bra.

“I have to admit that it’s spot-on, for what it is.” Sajuna said, now calmed down as much as she could be. The fantastical situation she was suddenly dumped into was so much that she felt like she had looped back around to calm, forced to take things at face value. “But you could have warned me first!”

“But it’s a surprise!” Marin protested. “I didn’t think it’d be that much of a shock.”



“You transformed in front of me! Magic is real! You’re lucky it wasn’t worse!” Sajuna snapped back at her. “Well, at least it explains that weird oni cosplay you posted the other day. I didn’t think you were that good at editing or making fake muscles, I knew something was up.”

“Now you know my secret!” Marin smiled. “And it can be your secret as you want too! There’s loads of other things to transform into on this thing! I know you don’t like to cosplay characters you aren’t a natural fit for, so maybe this can help? Although to be honest, a lot of them are weird or really specific, so it might not be that good for… Juju? You okay? You’re mumbling something to yourself.”

“Real magical girl transformation, real magical girl transformation, real magical girl transformation…” Sajuna was repeating the chant over and over, almost hyperventilating until she snapped out of it and looked at Marin with wild eyes. “Kitagawa! Let me see that app right now!”

“S-sure!” Marin handed her phone over, only to find Sajuna still staring at her.

“There’s no activation phrase for this, right? Like a call or magical words?” Sajuna asked intensely.



“M-maybe if you put a voice lock on the phone…” Marin laughed awkwardly.

“Well maybe there should be.” Sajuna’s hands trembled as her fingers hovered over the cowgirl screen.



“I’m gonna go get some more tea, okay?” Marin barely had time to turn around before she heard a squeak from Sajuna.

“Ah!”

Marin turned back to see Sajuna’s finger pressed firmly on the transform button instead of the back button.

“I-I was so excited that I slipped… How do you cancel this?” Sajuna whimpered, and Marin could already see her chest starting to grow…