Shuuji and Chise are third year students at a high school in Hokkaido. The shy Chise finally confesses to Shuuji, and the two are slowly starting to get to know each other better. One day, while trying to escape from a sudden enemy air raid on Sapporo, Shuuji witnesses a scene that he will never be able to forget. He sees Chise with what seems to be a huge weapon attached to her hand, shooting down the enemy fighters one by one. Apparently, Chise is the ultimate weapon with immense destructive power, crucial for the war effort.
