You can't decide what you want to go as so you just browse, as you go round the corner to the back of the shop, you slip on a bag someone has left lying on the floor, you try to grab something to steady yourself, but all you catch is a costume it comes of it's hanger, it feels as so it is giving off a static shock, you look at it, it is a Japanese schoolgirl's uniform. It has a blue pleated miniskirt, a cream shirt, a color and sleeve tips that match the blue of the skirt with a white stripe, and a red necktie, part of the shirt rather than a separate piece.
Without knowing how you know, you know that once touched by a customer, once taken down off the rack, a costume has to be left in the receptacle in one of the changing rooms to be collected for cleaning, pressing, and repackaging, before it can be put back on the shelves. This policy just pops into your head, and you can't find any willingness to violate the rules of this shop. Indeed, the mere idea brings you more than a little fear.
Luckily, noone sees you make your way into the changing room. So now you just have to place this costume in the receptacle and go find one you actually want. But it won't open. That's another rule, you realize. Since costumes have to be put in a receptacle once touched, it takes time for them to end up back on the rack, and work. For this reason, you can't just go grabbing costumes by the armload and dumping them into the receptacles. You can only grab one costume at a time, and you have to try it on and talk to the saleswoman. The idea of crossdressing in, what is to you, fetish wear, in public, is quite daunting at first. But then you realize that ending up with the wrong costume must happen a lot. So you shrug, double check that the door is locked, and take off everything but your boxers.
The store promptly reminds you that boxers do not match your current costume. You begin to think the store is alive and taking sadistic pleasure in all of this, but you don't really have a choice but to obey. The boxers come off too. Hidden inside the shirt of the costume are two bags. One contains a pair of shoes that will definitely not fit your feet, the other black stockings, garters, panties, and a bra. At this point, you know not to even think about skipping any part of the costume.
Panties first. Reasonably stretchy, they seem the most likely to fit okay. So you take a deep breath, and slide them up your legs. You've never crossdressed before, and are not excited by the idea of doing it now. You are unsure how to treat your penis in the panties. Eventually though, you decide that underwear should cover it, so you stuff it in. You look at the mirror, hoping the bulge doesn't show too badly. The bulge... doesn't show at all. You reach down and touch your crotch, only to find a surprisingly sensitive slit. You stop touching it immediately, now really worried.
It takes you a bit to figure out the garter belt, but eventually you get it on, more or less in the right place, then you slide the stockings carefully up your legs. Sometime during that process though, the change completed, because when you look in the mirror again, all trace of body hair is gone, your muscles, while not gone, have taken on a far more feminine cast, your hips have widened, your jaw narrowed, your hair lengthened, and you now sport small but firm breasts. With brown hair and no trace of epicanthic folds, this is clearly a generic 'Anime Schoolgirl' costume, rather than the costume of a real Japanese schoolgirl.
You sigh, your voice sounding as different as you look, and set about putting everything else on. Readjusting the garter belt so the garters hang right, figuring out the zipper on the skirt, trying to clasp the bra... all of it is new, and annoying, but you manage. You sit down in the chair in the corner and put on the shoes, simple brown loafers. Your new body seems to come with new reflexes, your walk as changed as your face, but you don't let it bother you. This is humiliating, but you will soon have it sorted out.
You saunter up to the saleswoman and say confidently "There's been a mistake. I grabbed this costume by accident and-" she cuts you off, smiling smugly at you. "There is no mistake. Do you think you came here to find a costume for a costume party?~ No, you came here to find a new life. You're incredibly lucky to be given a second chance. A universe where you haven't ruined your chances of getting your degree with drugs and alcohol, where the only woman you ever loved hasn't already left, disgusted by your self-destructive behavior. You came to us, and we gave you what you needed. There's still accessories you can add to your costume if you want, but this overall was the best fit for you. Not what you wanted, what you needed~"
She so casually lays out all the things you try not to think about, but this new body has none of your addictions. Could this really be a second chance? But can you manage as a girl? No, a woman. This is a college uniform.
So you decide to...