An awesome idea strikes you as you start running and you shoot ahead of everyone else in mad determination, reaching the finish line ten seconds before everyone else. You wait to catch your breath as the girls run up, Maddi in second place, Amanda in third, and Liz in last place.
When you can finally breath, you reveal your plan to them. "Alright, here it is." you begin. "I will become an eighteen year old girl in skin tight jogging shorts and a fairly lose blouse. Liz, since you were in last place, you will become my loins. Amanda, for third place, you will become the panties that I will be wearing after the change occurs, and finally, Maddi, you will become my bra to hold my C cup breasts."
You begin to feel odd as the changes take place. You shrink a little from your 5'6 height, to about 5'4. Your hair grows long and you feel your features become softer. The bit of unwanted weight that you've always had disappears until you weigh about 111 pounds. Then your chest swells out as you grow two perfect C cup breasts. Finally, your clothes change. Your sweat pants shrink up, hugging your thighs as the legs ride up past your knees to about you mid-thighs. You see that your crotch appears to be completely flat and you rub your had against it to confirm.
You look up at the girls as their changes take place. Your breasts suddenly feel supported as Maddi vanishes. You confirm the presence of a bra by grabbing and squeezing your breasts and feeling the cloth touch them. Then Liz vanishes and you feel a tingling sensation run through your crotch area and into your pelvis as new organs grow inside of you. then Amanda vanishes and you feel the familiar presence of underwear around your waist, despite the unfamiliar sensation around your crotch.
You smile and begin walking home, realizing that you have no one else to race with until 4:00 tomorrow afternoon.