A year into the aftermath of the Holy Grail War, Shirou Emiya and Rin Tohsaka were now happily studying together in the Clocktower school for Maguses. This all changes after the beckoning of a Wizard Grand Marshal and a certain magic book. Their journey starts, and a new world awaits. "Even now, I'm still the bone of my sword."

The story of a boy, which people only know as the brother of one of the strongest Huntsman, finally making himself known. His whole life he was in the shadow of others, constantly compared to his brother, even neglected by his parents because he was considered weak. Even his semblance, an always active one that causes people and grimm to simply not realize his presence, makes fun of him.