The W-0 Unit is a secret special unit within the Europia United army that participates in the war against the Britannian invasion of Europe. Its command and operating staff are made of EU officers, while its troops and Knightmare pilots are composed of "Elevens", former Japanese who were recruited from the ghettos of "Île de la Cité" in Paris. This unit's duty is to undertake highly dangerous missions with low percentage of survival.