Carol Weiss was a quiet girl who spent most of her free time reading. She was overweight, she couldn't see anything without her glasses, and so she clearly wasn't the most popular girl of the school. She didn't felt concerned about this spell that was supposed to turn girls into boys, and she didn't feel any "inner boy" inside her. Besides, her best friend was a boy, Alan Smith, who also enjoyed reading. They usually read side by side in the library of the school.
Two days after Sarah had cast the spell, a group of jocks came to the library and asked Alan to join them for football. Alan politely declined.
"What about you ? Wanna join us ?" a jock asked Carol
"Why not. I shall burn some fat anyway." Carol gave the book she was reading to Alan, and she followed the jocks to the football field.
Carol was the only girl of her team. She discussed with her teammates and learned that several of them used to be girls, but they were as masculine as the other boys (maybe even more). When the game started, Carol could barely run. But the more she played, she grew taller and gained muscles while loosing fat. Her breasts also disappeared, but she was enjoying the game too much to worry about that. After half time, she removed her glasses, as she didn't need them anymore. She became a valuable player of her team: her body was tall, manly and muscular. Her jaw became squared, and unshaved. Her voice became as deep as any of the other boys.
But it was only after the game, when they were all having a collective shower, that her genitals changed and she grew a huge penis. Carl was quite proud of his new cock, and after the shower, he asked his bros for spare clothes, since he couldn't (and didn't want to) wear his old girly clothes anymore.
Before leaving school, Carl went back to the library and told Alan: "I'm hanging out with my bros. We'll go to a bar and drink some beer. Wanna join us ?"
Alan politely declined. Carl couldn't understand why Alan prefered reading (Carl didn't like reading), so he went to the bar to meet the other jocks. It was a very good evening.