Alien vs. Ninja(エイリアンVSニンジャ)

A band of ninja warriors, led by an Iga Ninja named Yamata, witness a giant ball of fire drop from the sky and crash into the forest. When the warriors find and attempt to identify the object, they discover aliens that attack and feast on them. Yamata and the survivors swear vengeance, but in challenging the aliens, they learn that their weapons have no effect.