"Eiyū Kyōshitsu -Honoo no Empress-" is set in a world where humanity has been devastated by the emergence of monstrous creatures known as Majuu. To combat this threat, the Rosewood Academy was established to train individuals with exceptional abilities, known as Heroes, who can protect the world. The academy is divided into classes based on talent, with Class S being the highest, reserved for the most skilled and promising students.

The protagonist, Blade, is a mysterious and seemingly ordinary boy who enrolls in Rosewood Academy. Despite his unassuming appearance, Blade possesses unparalleled strength and combat skills, far surpassing even the top students in Class S. His arrival disrupts the academy's hierarchy, as he challenges the notion that only those with flashy abilities or noble backgrounds can be true heroes. Blade's calm demeanor and unorthodox methods often clash with the academy's rigid structure, but his actions consistently prove his worth.

The story explores the dynamics between Blade and his classmates, particularly the fiery and determined Claire, who aspires to become the strongest Hero. Claire initially views Blade as a rival but gradually comes to respect his abilities and unique perspective on heroism. Other key characters include the stoic and disciplined Leon, the cunning and strategic Lana, and the enigmatic instructor, Professor Ein, who harbors secrets about the academy's true purpose.

As the narrative progresses, the students face increasingly dangerous missions, battling powerful Majuu and uncovering dark truths about the world and the academy itself. The story delves into themes of strength, justice, and the true meaning of being a hero, as Blade and his peers confront their own limitations and the moral complexities of their roles. The series balances intense action sequences with moments of character development, highlighting the growth of the students as they strive to protect humanity and forge their own paths as Heroes.