It was quite interesting to watch. I had just randomly picked an anime from Netflix and this was it.
The story centers around a boy named Akihisa Yoshii, the titular baka (idiot) of the story. He attends Fumizuki Academy in Japan, a school where the staff rigidly divides the students based on the results of their academic scores. At the start of the school, students are academically sorted by entrance exam test grades. The higher the grades, the higher the class, and the better the benefits. In this case, Class A is filled with the highest-scoring students; therefore, their classroom is filled with many prestigious items (air conditioners, fancy seats, laptops, a free snack bar, etc.), while the state of Class F is the complete opposite of that, representing the "bottom of the barrel" amenities, such as mats and low wooden tables.
Fumizuki Academy has a special system, whereby all the students are able to call forth Summoned Beings (Shōkanjū, or "Avatars" in the official English translation). These Beings are used for battles between classes with the goal of capturing (or retaining) the best classroom facilities. Since Class A is filled with prodigies, they all have strong Summoned Beings, while Class F has drastically weak ones in comparison. A teacher must authorize/supervise each battle, and the health and strength of each student's Summoned Being is based on their last test score in that teacher's subject (i.e. Math, History, etc.). The Beings lose points when struck by an opponent, and should their point count reach zero, the being and student are disqualified, and must take supplementary lessons with the strict remedial teacher, Nishimura (nicknamed "Iron Man"). However, if the student can leave the battle before reaching zero, these points can be replenished by taking a supplemental exam. The student's Being may then return to the battle.
On the day of the placement test, an intelligent girl named Mizuki Himeji suffers from a fever during the test and is unable to complete it, hence her reining in a score of zero. As a result, she is pigeonholed into Class F together with Akihisa. Akihisa, who dreams of the day when the academy would no longer be divided by grades, pitches an idea to his class to rule over the higher-level classes by conducting a Summoner War for both Mizuki's sake and to get more privileges. Aside from Mizuki (who happens to be the second-ranked student in Year 2), there is also the class representative Yūji Sakamoto, the bishōnen Hideyoshi Kinoshita, the perverted Kouta Tsuchiya (AKA Ninja pervert,Muttsurīni), and the tomboyish Minami Shimada, who struggles with kanji having recently moved from Germany. (Akihisa claims she is his worst enemy, but she actually has a crush on him and is reluctant to show it). Throughout the year, Class F attempt several Summoner Wars against higher-ranked classes.