The tail of Galvania

Galvania is a giant kingdom, second biggest in the world. It has its rival, Goldstein the biggest kingdom in the world. Galvania has a Magic academy in which, students are evaluated on their skills and then assigned a class. There are 6 total classes. F-class, the commoners get discriminated against and get assigned in F-class despite some having good abilities. Then there is D-class, C-class, B-class, A-class and finally, the S-class. Only nobels are assigned this class and it contains the academy's strongest students. The magic academy also sends their strongest students to fight in battles against Goldstein. Galvania and Goldstein have been at war since the last 200 years. There is also a separate party, The Fatui, which fights against Goldstein and Galvania. It has a large source of funds from secret parties of Goldstein and Galvania. The story starts with our protagonist, Sasori. He is a commoner who is one of the strongest. Despite his strength, he is put in F-class.