Mina spun around in her chair, kicking her legs as she waited for the scientists to speak up. “So what am I here for again?” She asked, not paying attention the first time they told her.



One of the men behind the mirror spoke up, “We invited you here to see how your naturally occurring mutiboobs effect our serums since we’ve never seen this phenomenon naturally occur.” He said.



“…am I going to be paid for this?” Mina asked nonchalantly.



“Yes.” The scientist responded quickly.



“Cool! Do whatever to me then!” She said, correcting her chair. “...Well, except making me fat.” She said in a serious tone.



“We can make sure of that but could you tell us why?” A scientist asked, grabbing a separate sheet of paper to write on.



“Well, I bought a fat serum since some of my friends really like them but I couldn’t see anything because of my boobs after the growing had stopped.” She complained to the worker.



“I see, well let’s not waste any time then.” He said, sliding through a vial with a neon blue liquid in it.



“Ha, it looks like my hair.” She said before drinking it down in one go. Her blue pigtails began to grow as a 01 tattoo inscribed itself onto her right arm. Her clothes started changing to a gray outfit with blue highlights. Mina’s breasts started to grow, pressing against the already strained outfit while her reached her hips and kept going. “What is going on?” Mina said aloud, noticing that her voice wasn’t normal anymore. It made her sound like english wasn’t her first language. When her changes stopped, Mina’s hair was at her legs and her breasts were nearly double Z cup. “Ahh! I’m Hatsune Miku!” Mina said, looking over her new outfit. She even sang a couple notes of “The World is Mine” for them.



While the scientists knew that her breasts were going to grow but there should have only been one pair since it was supposed to turn them in Miku entirely. They discussed what to do next as Mina started to deflate and her hair began to fall out. They slipped her another vial, one with a peach color serum inside of it.



Mina didn’t have anything to say about this one and just drank it down with a loud burp. Mina’s stomach started gurgling as it began to grow. “Are you kidding me? I said I didn’t want to be fat!” She said angrily while her hair began to turn blonde and growing longer. Her hair tied itself into a sumo wrestler bun as the pounds packed themselves on. Her breasts grew a lot more with the top pair getting a mole on her right breast. Mina couldn’t see but felt something was wrong when she felt a third pair of breasts swell into existence. Even with all her new fat in her arms and legs weighing her down, Mina felt like she was off balance. “Used to two pairs of breasts I am but now off balance again!” She said in her new russian accent, irritated by this new development.” Finally, Mina stopped growing as her clothes changed into a sumo outfit. She was now the famous russian sumo wrestler Nadia. “A sumo wrestler? Really?”



“Yes but it was our only multiboob serum on hand.” The scientist replies as the scribbled down notes. “So it seems that if you body is told to grow another pair of breasts, it just makes them underneath the first set.” He said while Mina shrunk back to her normal size and amount of breasts. The scientists sent another vial Mina’s way after her clothes returned to normal.



Mina drank down the red serum and felt her hair begin to grow. It began to straighten out and became more healthy and luscious. Her outfit began to merge into one large mass of fabric, growing longer while maintaining her favourite lime green color. It soon began to form a poofy princess dress with a high collar that almost stopped her hair from flowing down her back. A corset began to press into Mina, crushing her lower pair of breasts as it tried to tighten itself. It soon gave up and Mina could breathe again. She looked at her new princess gown, confused as nothing had really happened to her except for her hair growing longer. That confusion disappeared when she felt her ass begin to grow. Soon her ass met the fabric of her dress and began to push it back. Her ass was massive and now made her dress seem much more elaborate than it actually was since it was draped over her large ass. “Now that seems more like it.” Mina said with a smirk, checking out her junk in her trunk.



“Despite looking like a princess, she’s not acting like one. Let’s try the personality shifting one next.” The scientists discussed while Mina kept fondling her ass. Slowly but surely her ass shrank back to her normal size and her clothes returned to normal. The scientists pushed through a milky white substance.



“God I hope this isn’t what I think it is.” She said, drinking it down with caution. Once she tasted the serum, she drank faster knowing that it wasn’t what she suspected it to be. She was surprised that the first change made her hair start falling out into a short bob cut. Her face began to rearrange a bit, not by a lot but it was still noticeable. Her lime green attire began to bleach itself to a pure white. Her clothes began to cling together, forming into a one piece suit, and to her body. The material changed into spandex as her legs began to be shown off more and more until she was wearing a leotard. All that material formed into a golden badge on her shoulder where a red cape shot out. A large boob window opened up to show off the space in between her top pair of breasts. Her lower pair of breasts pressed against the spandex while blue gloves and boots adorned themselves on her body. Mina suddenly felt strange, she straightened up and started acting more serious as if she needed to be on guard. To the naked eye, it just looked like Mina was cosplaying as Power Girl. “Let me show you what I’m made of.” Mina said to an invisible admasary while taking a fighting stance.



The scientists jotted down notes while Mina did some punches and kicks, getting a couple in before her clothes and hair reverted to normal. Mina shook her head and got her surroundings after the personality changes wore off. “Subject seems disoriented coming out of personality change but didn’t seem to react to having more breasts than she normally should.” The scientists said as they slipped her a brown serum.



Mina had a disgusted look on her face as she drank down the brown serum. Her hair began to grow longer as her ears were pulled out to a point. Mina began to grow taller while her feet started hardening into hooves. Her ass began to grow again but this time taking on a more blocky shape as it began to fill with muscle and fat. Soon, her back pair of legs descended from her horse body as fur erupted from it. Her clothes began to form into a skirt to cover her lower privates while leaving her chest uncovered. Mina thought her change was over but knew she was wrong when her torso began to swell. Three more pairs of breasts joined the initial two bringing her total amount of breasts to ten. They were all the same size and all of them stacked together pushed up the top pair, making Mina unable to see. “Really? This many breasts is ridiculous.” She said trying to push them out of the way. “Two pairs are fine but this is completly undoable!” She said angrily. The scientists drown her out, watching a nearby clock tick down to whatever they were waiting for. Mina’s face began to push out as she was complaining, her teeth getting blockier as her nose connected to her mouth. Her torso and arms began to shrink as her breasts were pushed down onto her horse body, fur crawling up to cover Mina’s head. “Great, now I’m a horse with boobs! This is fantasmmmh!” She shouted angrily before it was cut off by horse noises.



The scientists began to press buttons all around their station, preparing the last serum for Mina. They didn’t say anything as they slid it over to her and watched her drink it down. Suddenly, large rings popped out of Mina’s hands and feet. The scientists pressed their buttons and large wires clamped onto the rings.



Mina was suddenly spread out as she felt like she was beginning to fill up. “W-what’s going on here?!?” She shouted as her hands and feet began to turn into a plastic like material. She began to grow, starting to take up more space in the large testing room. She couldn’t move her arms and legs, the plastic continuing to spread and limit her movement as she filled with more air. She was half the size of the room when half her body was a balloon, she was unable to move most of her body now. By the time she was done growing, she was the size of a parade float. “W-wait! Don’t let anyone see me-” was all she could get out before her face forced itself into a smile as the plastic over took her face. The scientists waited again for something else to happen to Mina. Suddenly, her hands and feet shifted to hooves as horns inflated on her head. Her smile pushed out into a snout while a giant cock and balls swelled into existence with air.



“Well, the inflatabull is ready for the parade.” A scientist said while all the others got up and went home for the night, drowning out the muffled moos of the parade float  and letting it sit there until they needed it.