You find something you recognize vividly, being a bit of a weeb. A neat frilly white blouse that looks sort of like something from a sailor suit, with a blue collar and trim, and a red bow that fits around the collar. When you pick it up, under it you find a skirt that matches the trim, knee-high white socks and white shoes, and a matching bra and panties.
Recognizing the characters on the label, you realize you've struck gold. This is a Japanese school uniform! Not only is your stupid weeb side going nuts, you can use it for the slumber party and probably won't raise any eyebrows- just claim you're an exchange student who only just came here.
Not hesitating for a moment, you hide it all in a bag and race back to your house to go and try it on. You lock your door, undress to just your boxers and start to try it on, hoping desparately that despite the small size it'll fit you...