The first arc hits like a perfect locked-room mystery: logical, propulsive, immediate. Then the show pivots into something weirder and messier, chasing philosophical questions about destiny instead of tidy case solutions. Ayumu never stops reasoning his way through impossible situations, but the real hook is watching him realize that some mysteries don't have the kind of answers you can deduce.
Ayumu Narumi has spent his whole life overshadowed by his older brother Kiyotaka, a celebrated detective and pianist who vanished two years ago. Kiyotaka's disappearance left behind his wife Madoka, Ayumu, and a puzzling message concerning the Blade Children. When a girl at Ayumu's school dies in what first appears to be a suicide, it turns out to be murder, and Ayumu becomes the prime suspect. Hunting for whoever framed him, he finds that the mysterious Blade Children are involved and are somehow personally acquainted with Kiyotaka. As murders and incidents tied to the Blade Children pile up, Ayumu works with school journalist Hiyono Yuizaki to learn what fate awaits them. Along the way he discovers what a threat the Blade Children pose, and that he and his brother are bound together more closely than he ever imagined. The series mixes mystery with drama and comedy.
