At Aoi Academy, where everyone wields magic, Kazuki Shikimori ranks at the bottom: he can cast only a handful of spells before his body crumbles to dust. His life upends when three classmates move into it all at once, drawn not to him but to his bloodline. Yuuna Miyama, Kuriko Kazetsubaki and Rin Kamishiro each pursue Kazuki's genes, certain his ancestry carries far more power than his meager spell count suggests.