Sometime in the distant future, mankind is forced to live in domed cities while the rest of the world is left to recover from years of environmental hardships. In the Siberian Dome-polis, professional gamer Gainer Sanga and mercenary Gain Bijou commandeer an Overman and lead a mass exodus out of the city.

An ordinary and unlucky high school student, Lu Mingfei, one day received an admission letter from Kassel College, a foreign private university. After hesitating and hesitating, Lu Mingfei decided to find out. So far, he has stepped into the world where the "Dragon" exists, his life has undergone earth-shaking changes, and he has embarked on the journey of "slaying the dragon".

A transfer student Asai Mugi is a painfully shy girl. She is so shy that she can't speak when she becomes seriously nervous. However, for some reason, she is spotted and recruited as a member of the drama club.

In deep space a battle wages between the forces of good and evil and the fate of the Earth hangs in the balance. The evil Neos Gold dispatches her invading forces towards Earth with only one aim: the total destruction of all mankind. Now it's up to Iczer 3 (the younger sister of Iczer 1) to defend the Earth from the deadly armada of Neos Gold, with only the Earth's single remaining battle cruiser on her side. But don't count her out; what Iczer 3 lacks in experience she makes up for in all-out enthusiasm.