Entitled "Kojiki no Gash Bell - Mecha Vulkan no Raishu -", "Konjiki no Gash Bell!!: Attack of Mechavulcan"
Kiyomaro was kidnapped by a large object, and he lost his consciousness on the way. When he came to, he was in the castle and surrounded by machines. Then, a monster named Dr. M2 appeared. Dr M2 told Kiyomaro to become his partner to conquer the magical world.