A long time ago, the demon fragments that were shattered in the universe are still plaguing the entire universe. An unknown villain is using these demon fragments to harm the world and has extended his claws to the Kingdom of Light. Ultraman Zero and his apprentice Ultraman Zeta bravely stood up and faced the enemy head-on. After a fierce battle, Ultraman Zeta chased the monster to the earth alone. On the earth, people formed a defense force to fight against the monsters that appear every day - the monster response mecha unit "Armory (storage)". In this unit is a passionate young man - Haruki Natsukawa. The moment the space monster arrived on the earth, Ultraman Zeta and Haruki met. From then on, the battle story of the two passionate young men began.