"Toshi Gordian" is a science fiction anime series set in a dystopian future where humanity is on the brink of extinction due to the emergence of monstrous entities known as "Gordians." These creatures, which appear as colossal, biomechanical beings, are impervious to conventional weapons and have decimated human civilization. The story centers on a group of elite pilots who operate advanced humanoid mechs called "Vectors," designed to combat the Gordians. These Vectors are humanity's last hope, as they are the only weapons capable of penetrating the Gordians' nearly indestructible exteriors.

The protagonist, Toshi, is a young and inexperienced pilot who becomes entangled in the conflict after a chance encounter with a mysterious girl named Aya. Aya possesses unique abilities tied to the Gordians, making her a key figure in the war. As Toshi joins the ranks of the Vector pilots, he must navigate the complexities of battle, the politics of the surviving human factions, and the enigmatic nature of the Gordians themselves. The series explores themes of survival, sacrifice, and the blurred line between humanity and technology.

The narrative unfolds through a series of intense battles and strategic maneuvers, with the pilots uncovering secrets about the Gordians' origins and their connection to human history. Key characters include Commander Ryu, a seasoned veteran who mentors Toshi; Rei, a rival pilot with a personal vendetta against the Gordians; and Dr. Kanzaki, a scientist whose research into the Gordians reveals unsettling truths. As the story progresses, alliances are tested, and the pilots must confront the possibility that their fight against the Gordians may have unintended consequences for humanity's future. The series balances action-packed sequences with moments of introspection, delving into the psychological toll of war and the moral dilemmas faced by those fighting for survival.