Oscar Saionji, a pupil at Zeltor Hero Academy, conceals his remarkable abilities entirely, opting to present himself as an ordinary, inconspicuous individual. His motivation? He simply believes it is cool.

Nevertheless, the eccentric individuals surrounding him—his stunning classmate Serena, Student Council President Aria, and his composed swordsmanship instructor Raven—slowly start to recognize his concealed power.

Faced with rivals, the student council, and even the Demon King obstructing his path, what genuine strength remains hidden beneath the chuunibyou antics that Oscar exhibits during classes and examinations?