Sin Kiske, the forbidden child of a human and a magically crafted biological weapon called a Gear, lives in a world where magic has replaced science, and scars from the Gear rebellion remain. Attending his parents’ taboo-breaking wedding, he encounters a mysterious girl with deep hatred for Gears, and their fateful meeting threatens to upend the world once again.
Sin witnesses his parents’ sacrifice and vows to confront Unika to learn her true motive.
Unika disrupts the peace ceremony, triggering a fierce clash as Sin tries to reach her true intentions.
Sin confronts Unika to prevent a new war, while Elphelt goes missing during a critical investigation.
Sin confronts his failures, Unika questions herself, and the true enemy's identity begins to surface.
Sin and Unika lose control as Future Nerville’s plan triggers a global Gear rampage.
With the world at stake, the warriors clash against a relentless power that threatens everything.
Sin leads a final charge to stop Nerville as allies unite and the fate of the world hangs in the balance.
Unika and Sin face a pivotal battle that will shape their futures.