"Mayoe! Nanatsu no Taizai Gakuen!" is a comedic spin-off of the popular manga series "Nanatsu no Taizai" (The Seven Deadly Sins), reimagining its characters in a high school setting. The story takes place at Liones Academy, where the main cast assumes the roles of students and faculty, engaging in humorous and exaggerated slice-of-life scenarios. The central premise revolves around the chaotic interactions between the Seven Deadly Sins, who are now students, and their counterparts, the Ten Commandments, who serve as the school’s disciplinary committee.

Meliodas, the leader of the Seven Deadly Sins, is the captain of the school’s cooking club, often causing trouble with his mischievous antics and obsession with Elizabeth, a kind-hearted student who works in the school cafeteria. Ban, the Sin of Greed, is a delinquent with a penchant for stealing and causing mayhem, while King, the Sin of Sloth, is a lazy yet skilled archer who frequently naps during class. Diane, the Sin of Envy, is a towering yet gentle student who struggles with her height and feelings for King. Gowther, the Sin of Lust, is an eccentric and emotionless student who often misunderstands social cues, leading to awkward situations. Merlin, the Sin of Gluttony, is a brilliant but aloof student who conducts bizarre experiments, and Escanor, the Sin of Pride, transforms from a timid student into a confident and overpowering figure during the day.

The Ten Commandments, led by Zeldris, enforce strict rules at the academy, often clashing with the Seven Deadly Sins. Their interactions range from comedic rivalries to over-the-top confrontations, with characters like Estarossa, Derieri, and Monspeet adding to the chaos. The series also features cameos from other characters in the "Nanatsu no Taizai" universe, such as Hawk, the talking pig, who serves as the school’s mascot, and Gilthunder, a strict teacher who frequently loses patience with the students’ antics.

The narrative is episodic, focusing on humorous and absurd situations rather than a continuous plot. Themes of friendship, rivalry, and school life are explored through exaggerated and often surreal scenarios, such as cooking competitions, sports festivals, and magical mishaps. The series maintains a lighthearted tone, with frequent nods to the original "Nanatsu no Taizai" series, reinterpreting its characters and dynamics in a modern, comedic context. The manga’s humor relies heavily on slapstick, wordplay, and the contrast between the characters’ original personalities and their high school personas, offering a fresh and entertaining take on the beloved franchise.