ARGENTOSOMA takes place in 2059 where hostile alien life-forces threaten to take over the earth. College student Takuto Kaneshiro and his girlfriend Maki Agata work as assistants to a scientist. During an laboratory experiment a bio-engineered creature (named Frank) comes to life and causes a tragic accident. The explosion disfigures Takuto and kills Maki. Approached by the mysterious Mr. X a grieving Takuto bent on revenge goes undercover in an anti-alien military organization known as Funeral Unit. Meanwhile after escaping the laboratory Frank meets an orphan who instinctively knows how to communicate with him. They too are recruited to join the fighting forces of Funeral Unit.