The show takes place in "Crest Land", set after the mysterious "B-Crystal" went berserk at the WBMA Headquarters. The main protagonist, Kamon Day, lives in the south area of Crest Land, and is an energetic boy who loves B-Daman. However, he lost his all past memories of B-Daman and his family, except for his big sister Aona who lives with him. One day, Kamon meets Garuburn, a B-Daman, at his local B-Daman shop, "B-Junk", and he finds Garuburn strangely familiar. Garuburn becomes his partner, and he returns to the B-Daman battles once again.