一个现代版的灰姑娘故事。珊曼（希拉里·达芙 Hilary Duff饰）在父亲的童话故事中长大，不料却成为了童话中的灰姑娘。父亲过世后，继母和同父异母姊妹的侮辱和亏待，令她的日子过得苦不堪言。她想考取普林斯顿大学，想逃离这个龌龊的小世界，珊曼把她的梦想和苦恼都诉说给一个亲密的网友，他是她心灵的依托，是她的白马王子。 万圣节的相见摧毁了吉娜的梦。眼前的网友，竟然是学校里有名的帅哥运动员奥斯汀（查德·迈克尔·墨瑞 Chad Michael Murray饰）。一个是平凡黯淡的女孩，一个是闪亮耀目的男生。幸好吉娜乔装打扮，没被人奥斯汀认出。二人如此不登对，心虚的吉娜落荒而逃，不小心遗下一部手机。 就像玻璃鞋被王子拣到之后的故事，奥斯丁拿着手机寻找自己的灰姑娘，而吉娜，却无法相信自己怎会像灰姑娘般幸运。于是这出爱情故事，注定充满曲折而窝心的波澜起伏。
Samantha 'Sam' Montgomery (Hilary Duff) lived a semi-fairytale life with her widowed father when she was 8 years old in a suburb in California. Later, her father opened up a Diner named after him and fell in love with a woman named Fiona (Jennifer Coolidge) who he later married. One day, a falling support beam kills her father in the 1994 Northridge earthquake and leaves her with her plastic-surgery-salmon-eating-obsessed stepmother and her two cruel stepsisters Brianna (Madeline Zima) and Gabriella (Andrea Avery). 10 years later, Sam is a straight-A student enduring her uncaring stepmother's wrath, who turned her father's cafe into a girly hot-pink hot spot and forces her to work as a "diner girl". In addition to her family, Sam must deal with the "popular" girls at school, led by the lead cheerleader, Shelby (Julie Gonzalo) who, according to Carter (Dan Byrd) "wants him so bad". Sam confides in her best friend Carter and cyber-space, pen-pal, her "secret admirer" who wants to attend Princeton with her. What she doesn't know is that her secret admirer turns out to be Austin Ames (Chad Michael Murray), quarterback of the football team and the most popular boy at school who is currently dating Shelby.
As they text each other back and forth, Austin (or, as he refers to himself in cyberspace, "Nomad") invites Sam to the Halloween Dance so they can meet face-to-face. Austin dumps Shelby a few hours before the dance. At the same time, Fiona forces Sam to work late at the diner that night until midnight. Carter, Rhonda (Regina King) - Sam's mentor and friend at the diner who also works there, and the other cafe employees help Sam get to the dance, masquerading as Cinderella in a mask and Rhonda's wedding dress. She meets Austin in the middle of the dance floor and is at first put off by the fact that her "Nomad" is Austin. He soon wins her over, and they move outside together. They play "10 Questions", Sam never revealing her identity, as they dance outside in a gazebo. However, Sam's cell phone alarm goes off 15 minutes before midnight, warning her to run back to the diner before she's caught, leaving Austin without Sam's real name. Austin and Sam, or Prince Charming and Cinderella are chosen as the Homecoming Prince and Princess but "Cinderella is playing hard to get". As Sam and Carter flee the dance, once Sam has managed to pull Carter (or Zorro who he went as) away from Shelby who he is kissing after he prevented David, one of Austin's friends, from making a move on her, Sam drops her cell phone and Austin picks it up, determined to find out who this "Cinderella" is.
Sam goes to school the next day to find Austin performing a school-wide search for his Cinderella. Sam is still feeling uncomfortable about revealing herself to Austin, who in turn is still searching obsessively. One afternoon, Sam's stepsisters find her emails while snooping around on her computer. After unsuccessfully trying to pass themselves off as Cinderella to Austin, they end up showing the emails to Shelby and her friends. The stepsisters make her believe Sam stole Austin on purpose, so she puts together a cruel skit to perform at a football pep rally in order to humiliate Sam. The skit is performed in front of the whole school, as well as Austin's father who is present at the pep rally and has been pressuring Austin to attend college to play football at USC, his alma mater. Austin has never told his father he really wants to attend Princeton University.
Hurt and humiliated, Sam goes back home and Fiona brings her a letter from Princeton saying that she wasn't accepted. This is, in actuality, a fake letter as Fiona and the stepsisters threw out the real letter from Princeton which said she was accepted (most likely so she wouldn't leave the diner). The next day, after Brianna and Gabriella slam the door so the guitar with Elvis on falls down, ripping off the wallpaper and exposing a quote that says "Never let the fear of striking out, keep you from playing the game" and blaming this on Sam, she reads this aloud and decides she has had enough of her step-family and their abusive treatment. She quits working at the diner, tells Fiona that "she can mess with her hair, her nose, her face and even her dad's diner, but she's through messing with her", and moves in with Rhonda. The night of the big football game, Sam storms into the boys locker room and confronts Austin, saying that she's fed up with his two different identities, one to her and one to his friends "Waiting for you is like waiting for rain in this drought, useless and disappointing." In the last few moments of the game, as the game is about to start again and Austin is going to score the touchdown the North Valley Fighting Frogs need to go to the semi-finals of the State Championships, Austin sees Sam leaving and abandons the game, but as he is running off the pitch, his father grabs him and asks him what he is doing, throwing away his dream like that, to which Austin replies "no dad, I'm throwing away yours", and makes up with Sam and kisses her, at the very same time it starts raining.
