Two bonus episodes that take place during the course of the series, approximately halfway through it seems. They are entitled 'Everything you always wanted to know about Nereids (but were afraid to ask)' and 'Heaven can wait for Maia Mizuki'. These stories are more lighthearted and comedic in tone, bordering on silly.

Rushuna is a blonde and very beautiful Senshi (gun expert) that travels through the world with one purpose. Which is to make the world a peaceful place by, instead of fighting with weapons, taking away the people's will to fight by giving them a smile. Although she doesn't want to fight, she is forced to, and shows amazing gun skills. In this journey she meets Yajirou, a mercenary that uses a sword to fight and joins her on her journey. (Source: ANN)

This is a world of the skies, where many islands drift in the sky. A boy named Gran and a talking winged lizard named Vyrn lived in Zinkenstill, an island which yields mysteries. One day, they come across a girl named Lyria. Lyria had escaped from the Erste Empire, a military government that is trying to rule over this world using powerful military prowess. In order to escape from the Empire, Gran and Lyria head out into the vast skies, holding the letter Gran's father left behind—which said, "I will be waiting at Estalucia, Island of Stars." (Source: Aniplex of America)

By the advent of the 21st century, much of humanity was dead, having been trampled over by a new master, Godzilla. A select few among mankind took to the stars in a spacefaring vessel called the Aratrum in search of "the promised land," the planet Tau-e that could sustain human life. But the migration plan fails, and the remnants of the human race decide to return to Earth. But the distortions in space-time and the distance traveled means that mankind is returning to a completely changed Earth some 20,000 years later. The returnees, led by hero Haruo, prepare to take the fight to Godzilla based on a strategy that has been 20 years in the making. Carried out with the help of two alien species, the Exif and the Bilusaludo, the humans succeed in defeating Godzilla in a costly battle to the death.

But the victory is short-lived. Rising from the depths of the planet is a new breed of monster, dubbed "Godzilla Earth." Evolving for 20,000 years, the creature stands 300 meters high, weighs over 100,000 tons and wields such overwhelmingly destructive power that Haruo and company have no choice but to run for their lives.

Coming to Haruo's rescue, however, is Miana, a member of an aboriginal tribe called the Houtua. They are the first humanoid people the returnees have encountered. Could they descend from humans? "Our tribal god was destroyed by Godzilla. All that we have left are these eggs. Anyone who has tried to fight or resist him has been drowned in fire," the tribespeople say to Haruo, who responds with: "This is our last hope of recovering our home."

Meanwhile, Bilusaludo commander, Galu-gu is elated to discover that the Houtua tribe's arrowheads are made of a nanometal or a self-sustaining metal. It had been developed in the 21st century as an "anti-Godzilla" killer weapon deployed at their decisive battle fought at the foot of Mt. Fuji, but had been destroyed before it could be activated in the form of a "Mecha-Godzilla." The nanometal was its base substance, and proof that the manufacturing plant can still be used.

(Source: Official site)