You're a twenty year old bisexual woman, from a large American city. You spent a long time searching for a train last night, and you finally found one. You always did have a kink for neutered guys. As you sit on the train now, you're kind of turned on, and have to avoid maturating in a car where people can see you.
Suddenly you're awoken from sleep, wondering for a momment if the train was a dream, and very quickly feeling that it was certainly not. Your body feels different, you aren't quite sure how but it's diffrent.
You sit up and notice that you're purportioned differently. You might be a bit taller, having gone from 5,3 to about 5,6, and you're limbs especially feel longer. Your bones also feel weirdly soft.
Your skin feels so sensitive. You can feel the soft cloth of your pajamas on it so easily. You realize you don't have any hair outside your head, and feeling your skin you realize that you lack most adult blemishes. You also suddenly feel your chest, being entirely flat, the large breasts you were once proud of being nonexistent, and likewise your wide hips are now androgynously narrow.
Sitting in your room you realize this body never went through puberty. You're an adult, but you must have had your ovaries snipped away as a kid, turning you into whatever you are now.