Plot synopsis: Advanced placement into a school of higher grade proof-reading is determined by the results of the Promotion Test strictly for class type. Ranging from A class with the best facilities anyone can offer all the way down to F Class which is composed of low dining tables, rotten tatami mats and other worn out facilities. Students can change classes by competing using the Examination Summons Battle system or ESB. Students summon characters with their equivalent test mark scores and use them to compete with other classes.