Center-sensei no center šiken (E06)

Just as the group is about to get used to the strange class, it's time for their Center Exam. They'll be going into the world of "Border Break" and piloting Blast Runners in an attempt to destroy the enemy's core. Since this exam is important, they'll be getting far more medals than usual. But during the exam, Center-sensei has an emergency message. (Crunchyroll)