The story centers around a boy named Akihisa Yoshii, also known as the idiot or "Baka" of the title. He attends Fumizuki Academy, a school where the staff rigidly divides the students based on the results of their tests. In this case, Class A is filled with the highest-scoring students; therefore, their classroom was filled with many prestigious items (air conditioners, fancy seats, huge spaces, etc.), while the state of Class F is the complete opposite of that, leaving much to be desired. This academy has something special, where all the students manage to call forth Summoned Beings (Shōkanjū). These Beings, whose strengths are measured by their summoners' grades, are used for battles between the classes. Since Class A is filled with prodigies, they all have strong Summoned Beings, while Class F has drastically weak ones in comparison.