It is the dark century, and the people suffer under the rule of the devil Vandel, who can manipulate monsters. The Vandel Busters are a group that hunts these devils, and among them, the Zenon Squad is known as the strongest busters on the continent. A young boy named Beet dreams of joining the Zenon Squad. However, one day, due to Beet's fault, the Zenon Squad is defeated by the devil Beltose. The five dying busters sacrifice their life power into their five weapons, Saiga. After giving their weapons to Beet, they pass away. Years have passed since then, and the young Vandel Buster Beet begins his adventure to carry out the Zenon Squad's will to put an end to the dark century.