All the way from the other dimension, their long-lost mother, Mio Minato finally returns to the family! It seems that Mio was finally able to escape the grasp of the vicious kaiju, Kamisori Demaaga, and reunite with her family after 15 long years! Ushio is extremely impressed by what she has done, however Katsumi and the others, who haven’t known their mother for very long, seem somewhat confused. Just then, Saki Mitsurugi feels the pulse of the Earth’s ray energy, and the vicious kaiju, Kamisori Demaaga’s excavation towards the Earth’s core! Saki intends to destroy Kamisori Demaaga in order to protect the precious energy, however…