In the Age of Interplanetary Wars, Earth is in danger from those who would threaten its very existence. From their massive underground complex near Mt. Fuji the Ultra Guard, an elite unit of the Terrestrial Defense Force, stands vigilant as our decisive first-line of defense. But unbeknownst to his teammates, Dan Moroboshi is secretly an extraterrestrial aiding them in their fight to preserve the future of humanity. Dubbed Ultraseven, he aides the Ultra Guard in fighting back alien hordes that would doom the world to conquest.

A far greater threat emerges, though, as Ultraseven sees the consequences of his power: can he maintain his soul in the face of constant violence, even when that is necessary to protect his newfound friends?