The final volume centers on the ultimate attempt to suppress Beyond the Boundary once and for all. The core conflict rests on a tragic paradox: to completely destroy the threat of Beyond the Boundary, Akihito's youmu half must be eradicated, which threatens his very survival.
The climax of the light novel centers on the battle against the (Kyoukai no Kanata), the most powerful and malevolent youmu in existence, which resides within Akihito. In the novels, the conflict is deeply tied to the secret history of the Spirit World Warriors and the Curse of the Blood. beyond the boundary light novel ending