Cartoonist "Hoops" McCann (John Cusack) is busy working on his scholarship application for the Rhode Island School of Design (RISD) as the day of his high school graduation approaches. Coming from a family of professional basketball players, he faces a setback when he’s denied a sports scholarship for his dismal performance on the school basketball team—he hasn't managed to score a single basket. Despite his athletic heritage, Hoops struggles even with throwing a paper wad into a trash can, a recurring gag that adds humor to his character.
At graduation, he reunites with his closest friend, George Calamari (portrayed by Joel Murray), who convinces him to spend a couple of weeks partying on Nantucket Island. George picks up his feisty 10-year-old sister, Squid (Kristen Goelz), and her injured dog, Bosco. When a group of girls mocks Bosco's appearance, Squid fiercely retaliates, putting them in their place.
During a pit stop for gas, a group of bikers led by Stain (John Matuszak) is on the lookout for a woman named Cassandra (Demi Moore). Hoops unwittingly finds her stash of cash hidden in a towel dispenser and haphazardly tosses the bills into the air while fleeing with Cassandra to George’s car. They make a daring leap onto the departing ferry, leaving Stain floundering in the bay—a scene both chaotic and comedic.
Once on the island, Cassandra reveals she’s visiting her grandfather, Mr. Eldridge. Their initial connection hints at deeper affections as she expresses her concerns over her grandfather's financial troubles and the risk of his friends becoming homeless. As Hoops tries to lift her spirits, he draws cartoons featuring whimsical animated sequences, such as a "Lonely Rhino" in search of love, adding a creative flair to the story.
Their trip is filled with youthful shenanigans, including the introduction of the awkward but lovable Stork twins—Clay (Tom Villard) and Egg (Bobcat Goldthwait), who are currently working as security guards on a film set for an absurd horror movie about a rabid dolphin.
As life unfolds on the island, Hoops struggles with romantic decisions, caught between going to see Cassandra play at the local inn or attending a movie with George's friend Cookie Cambell (Kimberly Foster). Unfortunately, his conflicting commitments dilute his chance to support Cassandra during her performance. Events heat up when Egg, absurdly still dressed in a Godzilla costume from the film set, inadvertently crashes a fundraiser being held at the estate of the powerful Beckersted family, leading to a series of comical mishaps.
Back at the drive-in, tensions rise between characters, leading to comedic confrontations, especially when Teddy Beckersted (Matt Mulhern), the entitled son of the family, feels threatened by Hoops’ growing bond with Cassandra. A challenge ensues between Hoops and Teddy, culminating in Hoops' hilariously poor basketball skills being put on full display, leading to further chaos as Cassandra bravely steps in to defend him.
As the summer progresses, Hoops rallies his friends to help Cassandra fundraise by launching a concert, which culminates in loud, lobster-filled shenanigans against the Beckersted family’s attempts to thwart her efforts. Even after facing numerous setbacks, including a heart-wrenching injury to Squid's beloved dog, the group’s determination shines through. They decide to enter a sailing regatta with Cassandra, where they confront Teddy’s team head-on.
On race day, amidst a lackluster boat and ridicule from the crowd, they face sabotage but manage to turn the tides through clever improvisation. In a climactic finish, Hoops defies all odds and manages to score—a symbolic gesture that illustrates his growth and determination throughout the story. The victory leads not only to triumph over Teddy, but also to the return of Mr. Eldridge's estate to Cassandra.
In the end, Hoops and Cassandra share a heartfelt moment, sealing their newfound connection with a kiss. The report of George's uncle finally winning a million-dollar contest before his fate takes a wacky turn serves as a perfect comedic capstone to this adventurous summer tale. As they all celebrate with joy, the group learns valuable lessons about friendship, perseverance, and the unpredictability of life.
