A kid discovers he's not human right as the world starts ending, and suddenly he's the only one who can pilot a mecha that shouldn't exist. Three beast-warriors from another dimension are supposed to save Earth, but they're fighting blind because they don't know what Touya actually is. The show builds its entire momentum on the fact that nobody, not the heroes, not the invaders, not Touya himself, knows the full picture of what's actually happening.
Touya's ordinary life shatters when he discovers he's not human at all, but a being from the mystical realm of Eternalia. His awakening comes none too soon: monstrous Darknoids from the twisted world of Nosfertia have begun a systematic invasion of Earth, and conventional defenses crumble before them. Standing between total annihilation and salvation are three Animanoids, humanoid warriors blessed with beast forms and combat powers beyond mortal comprehension. They arrive from Heavenstia with a single mission: stop the invasion. But they can't do it alone. Touya's true nature grants him abilities no one understood he possessed, making him the crucial fourth piece of a desperate resistance. What unfolds is a collision between worlds. Touya must learn to control newfound powers while fighting alongside creatures that blur the line between human and animal. The Darknoids grow stronger with each assault, and every battle raises the stakes higher. With three different dimensions at war, Touya learns that his identity carries weight far beyond his own survival.