Benjamin Fiedler (DARYL SABARA) is a typical teenage boy who lives with his dad Adam (JEREMY PIVEN), mom Joanne (JAMI GERTZ) and Adam's mother Rose (DORIS ROBERTS), and is dreading his Bar Mitzvah that's quickly approaching. That's not only due to being worried about speaking in front of a crowd or trying to impress schoolmate Ashley (BRITTANY ROBERTSON), but also because he's just attended the same ceremony for his friend Zachary (CARTER JENKINS).
That boy's father, Arnie Stein (LARRY MILLER) -- Adam's former business partner in the talent agency field -- has just thrown the Bar Mitzvah to end all such events, and Adam feels he has to compete in order to save face. Realizing that will only mean added anguish for himself, Benjamin decides to try to divert his dad's attention by inviting his long-estranged father, Irwin (GARRY MARSHALL), and girlfriend Sandy Frost (DARYL HANNAH) - a.k.a. Sacred Feather -- to the big event.
Irwin walked out on Rose and Adam 26 years ago, and Adam has never forgiven him for that or embarrassing him at his own Bar Mitzvah. Accordingly, he's not pleased when Irwin and Sandy show up unexpectedly and two weeks early. As those two try to sort out their feelings about each other, Benjamin prepares for his big day, all while getting advice and encouragement from them, Rabbi Schulberg (RICHARD BENJAMIN), Zachary and others.