What value does unlimited magical power hold when instant death can obliterate everything in a single blow? For Yogiri Takatou, this question becomes urgently real. A dragon ambush during a high school field trip leaves Yogiri and his classmate Tomochika Dannoura as sole survivors aboard the devastated sightseeing bus. Their peers managed to escape—but only after Sion, introducing herself as a Sage, granted them special powers in advance. Those denied such gifts, including Yogiri, were deliberately left behind as dragon bait. Thrust into a treacherous parallel universe stripped of context, Yogiri struggles to comprehend what happened. Sion remains dangerously ignorant of the true nature of the being she has summoned into her world.