Humans are sapient species originating from Earth. Due to overcrowding and pollutions, the Earth nations began to develop space colonization and HBT fuel to ease the situations. Since 2050, majority of human civilization has been residing on Mars and other interstellar colonies after the Inbit's conquest of Earth.
By the early 21st century, the human civilization has developed hydrogen-based fuel called HBT to solve energy crisis while also reducing the pollution levels. Furthermore, it allowed colonization of Mars,Moon and other planets in the solar system thanks to the new HBT energy source powering interstellar ships and life-support systems. Suddenly on 2050, a wave of alien invaders known as Inbits landed on Earth and forced many of the residents towards the colony while those who were left behind were either scattered to isolated rural communities or self-sufficient and advanced cities that collaborated Inbits. Mars and other colonies would gather resources and manpower for Earth Liberation Forces in 30 years, though there were instances of intercolony conflicts such as a rebellion on Jupiter in 2076 and pirate activities on Saturn in 2077--both of which Johnathan participated before his assignment to First Liberation. First invasion in 2080 ended in disaster along with the succeeding invasion in 2083 even with the development of MOSPEADA and Legioss fighters to combat the Inbits. By 2084, the colonies develop Shadow stealth systems, Synchron weaponries, and even unmanned fighters for Third Liberation campaign which also had the support of surviving troops from first and second campaign. Initially, the battle went smoothly to the point of a handful of unmanned fighters reaching the hive but suffered heavy losses when Inbits launched a counter attack. In desperation, the fleet launched particle missles at Earth that would destroy large parts of Earth's surface. Fortunately, Refless was convinced by Stig, Aisha, and the group to abandon Earth who then dispelled the missiles after learning the error of her ways. After 34 years of conflict, the Earth is finally back in humans' hands and rebuild all their cities on Earth.
- Majority of the named characters had non-Japanese names, save for Shinobu Takeuchi, which would be due to multi-ethnic nature of human civilizations along with the show's plot being set in the continent of Americas.
- Oddly enough, large numbers of non-Spanish names--especially in South Americas--may either be due to production oversight or the result of expatriates before the Inbit Invasion along with refugees who fled to the area.
- Details on Mars and other colonies has not been explored save for their more advanced infrastructure and government that allowed the humans to create a military for three Earth Liberation Campaigns.