Freddy Shoop, a laid-back high school gym teacher, is eagerly anticipating his summer vacation in Hawaii. His plans are abruptly halted when Vice Principal Phil Gills assigns him to teach a remedial English class for underperforming students during the summer. Shoop, inexperienced and completely unprepared for the task, reluctantly agrees to teach the motley group of disinterested students after being bribed with promises of tenure. The class is composed of a diverse group of underachievers, each with their own quirks and reasons for needing summer school. From the rebellious surfer to the aspiring makeup artist, these students are more interested in sunbathing and skateboarding than cracking open books.

As the summer rolls on, Shoop finds unconventional ways to reach his students, making deals to help them with their problems in exchange for a slight effort in their academics. Slowly, he earns their trust and respect by addressing their individual issues while creatively engaging them with lessons that extend beyond traditional academics. Meanwhile, Shoop's casual approach to teaching attracts the attention—and disapproval—of Gills, who continually threatens to fire him if test scores don't improve. As Shoop and his students form a unique bond, the unlikely group begins to realize their potential. However, with Gills watching closely, Shoop must find a balance between keeping his job and inspiring his class to succeed against the odds.