This body-switch comedy stars Jennifer Garner and Mark Ruffalo. In 1987 a 13-year-old girl named Jenna wishes to be grown up and is transformed into a woman. The adult Jenna (Garner) now finds herself in the year 2004 as a 30-year-old magazine editor with the brain of a teenager. As she tries to find out what happened during the intervening 17 years, Jenna gets reacquainted with childhood friend Matt, now also grown up and played by Ruffalo.