A private agency called Black Balsam serves poetic justice for victims of crime against their wrongdoers. It compensates for the ineffectual police in the Republic of Taured, in a world where special abilities called Astras are distributed among the population. Led by a vulture-masked shapeshifter dubbed Cathartes and his sharpshooting partner Haliaeetus, it gains a following as a revenge-for-hire group. However, it becomes unclear if its motives are upholding justice or ensuring the elegance of vengeance.

An original light novel.