A ruthless fight breaks out in a laboratory guarded by the army... Under a hail of bullets, the attackers manage to escape with a sample of a top-secret biological weapon! Meanwhile, it's the start of a day like any other for the students of the 1st A class at Kaishin High School... Until the group of thieves show up at the school! They barricade themselves inside, taking teachers and students hostage. Who are these terrorists armed to the teeth? And what are they fighting for?