On the first morning of their last year of high school, we see four seniors having a "Security Meltdown." Calvin frets about the size of his nose, which prevents him from pursuing the girl of his dreams, Rosanna. Rosanna is having a meltdown of her own, yearning to find her "thing" and be more than just a pretty face. Calvin’s best friend, Bret, longs to be seen as a potential girlfriend and not just a girl friend. Matt, the handsome new kid in school, fears that his poor speaking skills will keep him from making friends.
Calvin’s school year starts with a bang: Rosanna speaks to him for the first time, inviting him to a meeting for a new charity she is starting. She then has a bumbling encounter with Matt, and though they are perfect strangers, there is instant attraction ("I Can See Him Now").
Later, Calvin and Bret are in study hall chatting about movies. Rosanna interrupts and asks Calvin to meet her that night ("Don’tcha Think?"). He takes this to mean a date, and shows up with a love poem for her… only to hear her confess her feelings for Matt. She asks Calvin to speak to Matt, since they are both on the wrestling team, and find out if he likes her. Though heartbroken, Calvin agrees ("It Just Wasn’t Meant to Happen"). In the locker room the next day, Calvin speaks to Matt, who says he likes Rosanna but gets tongue-tied around girls. Calvin laments having the opposite dilemma: verbal wit without good looks. In a hilarious duet called "We’re The Man," they hatch a scheme to win Rosanna’s affection by combining Calvin’s words with Matt’s looks.
In preparation for Matt’s first date with Rosanna, Calvin writes love notes for Matt to give her. He tries to coach Matt on what to say, but discovers that Matt has a lousy memory… except for rap lyrics. Thus, Calvin must — quite awkwardly — teach Matt through the use of rap ("Never Know"). When the big night comes, their plan works like a charm. But it pains Calvin to see Matt kiss Rosanna.
Alone in her bedroom, Bret wishes she was with Calvin instead ("Saturday Alone"). Just then, Calvin calls and invites her over. She shows up at his house dressed to the nines, but he just asks her for help writing love notes to Rosanna.
Back at school, Calvin playfully asks Rosanna how things are going with Matt. In "More Than Meets the Eye," she raves about Matt’s brilliance and says she loves him for his beautiful words, not his looks. Calvin is stunned to think Rosanna really loves him. Calvin writes Rosanna a note confessing his feelings, and explaining that the words she has fallen in love with are his ("Act One Finale").
Calvin shares a playful moment with his Mr. Potato Head doll, envying its ability to change facial features ("Mr. Potato Head"). He then takes the confession note to Matt to give Rosanna that night. To Calvin’s dismay, Matt has decided he no longer wants help ("Graduation Day"), but Calvin convinces him to deliver this one final note. Calvin cancels plans with Bret for that night ("Saturday Alone" Reprise), so he will be ready when Rosanna learns the truth.
On the date, Matt hilariously blunders and calls Calvin begging for assistance. In an update of Cyrano’s balcony scene, Calvin feeds Matt lines through his cell phone earpiece. Things go awry, and Rosanna storms out before Matt can give her Calvin’s last note. Growing suspicious of Calvin’s motives, Matt reads the note himself.
Calvin is confronted by Bret, who is fed up with his insensitivity to her feelings, and by Matt, who now sees that Calvin was using him. Rosanna looks on and learns that she’s been tricked. Suddenly everyone is screaming at Calvin ("The Fight"). The scene culminates with Calvin getting punched in the nose and everyone singing the quirky lament, "How Can I Compete With That?"
The final scenes crescendo to a "Bachelor Auction" that Rosanna has organized for her charity. Calvin must make amends with the other characters, especially Matt ("We’re The Man" Reprise). Along the way, he realizes that Bret has secret feelings for him ("Perfect For You"), just as he does for Rosanna. He questions which of the two girls is truly right for him, and realizes the answer was right under his you-know-what. Meanwhile, Matt must win back Rosanna’s affection without assistance from Calvin, and Bret and Rosanna share a moment of female bonding ("Calm, Cool and Collected"). By the time the four friends take their places for the Bachelor Auction, each has found new self-confidence and acceptance of their own imperfections ("Finale").