"Cromartie High School" is a comedic manga series set in a fictional high school notorious for its delinquent student body. The narrative revolves around Takashi Kamiyama, a seemingly ordinary and intelligent student who transfers to Cromartie High. Despite his academic demeanor, Kamiyama quickly becomes entangled in the school's bizarre and chaotic environment, where the students are more preoccupied with absurd antics than actual delinquency.

The school is populated by an eccentric cast of characters, including Mechazawa, a robot who blends in as a regular student; Gorilla, a literal gorilla who attends classes; and Freddie, a parody of Freddie Mercury who rides a motorcycle and frequently breaks into song. The series thrives on surreal humor, with each chapter presenting self-contained, often nonsensical scenarios that parody typical high school tropes and delinquent stereotypes.

Kamiyama serves as the straight man amidst the chaos, often reacting with bewilderment to the absurd behavior of his classmates. Despite his initial reluctance, he gradually becomes an integral part of the school's peculiar social dynamics. The plot lacks a conventional overarching storyline, instead focusing on episodic humor and satirical commentary on school life, authority figures, and societal expectations.

The humor in "Cromartie High School" is rooted in its deadpan delivery and absurdist situations, such as students debating the logistics of a gorilla attending school or Mechazawa's existential musings about his robotic nature. The series frequently breaks the fourth wall, with characters acknowledging their roles in a manga and commenting on the absurdity of their circumstances.

While the narrative does not follow a traditional progression, recurring themes include the futility of violence, the absurdity of social hierarchies, and the unpredictability of human behavior. The interactions between characters are often unpredictable, with even the most mundane situations escalating into surreal and comedic chaos. The series maintains a lighthearted tone, using its unconventional setting and characters to explore humor in unexpected ways.