Twins Andie and Caitlin are best friends but they couldn't be more different. Andie loves sports and hanging out with her friends -- Caitlin is passionate about music and loves learning at school. <p>Now that Junior High is starting, the girls will finally get a chance to pave their own way. They can't wait! <p>But when Caitlin discovers she'll have to pass a fitness test or spend every day after school doing gym, she fears her year is ruined before it even begins.<p>If only someone could take the fitness assessment for her.<p><p>The girls make the switch. While Andie passes the fitness assessment for Caitlin, Caitlin goes to class for Andie. Everything goes great -- maybe TOO great. Now it seems like the girls keep wanting to change places "just one more time."<p><p>With each switch the girls get in deeper. Will they be able to straighten things out before they're in over their heads?