Baka & Test - Summon the Beasts

Story:

The protagonist is a guy who is among the stupidest of the stupidest in the school. In this school your grades can, under the supervision of teachers, take a virtual form to do battle! However, if you leave an examination midway, you get zero marks. A bright and cute girl, Mizuki Himeji, had a high fever during her examination. Despite her potential to be the second highest scorer in the level, she obtained zero marks for having left due to her illness and is thus banished to the worst class, Class F.