Sometime in the past, the people of the country of Parts had found a way to become immortal, but only with elderly nobles. Five of these elders—Ballossum Pench, Gabriel Hammer, Jimchuck Spanner, Olsorro Slasher, and Leonard Drill—obtained immortality, and became known as the Motoruin sages. Eventually, they attempted to take over the Parts kingdom and start a new world order, collapsing the government and destroying parts of the country in the process. As their plans unfold, five children of one of these villages decide to battle the Motoruin using another new invention: the semi-automatic propelling engine, known as "Progear".