Kakumeiki Valvrave is set in a future where humanity has colonized space and is divided into two powerful warring nations: ARUS and Dorssia. A neutral faction, JIOR, tries to remain peaceful between them.
The story follows Haruto Tokishima, a student living on a JIOR colony, whose life is shattered when Dorssia attacks, seeking powerful mecha called Valvraves.
Haruto unexpectedly finds a Valvrave and, in a moment of desperation to protect his friends, makes a dangerous contract to pilot it, sacrificing something precious in the process.
Along with L-elf, a mysterious strategist from Dorssia, Haruto uses the Valvrave to fight back and begins a revolution to free themselves from the conflict between the superpowers.