Light novels arrive in volumes, and reaching a fourth is a vote of confidence cast by readers rather than publishers. Skeleton Knight in Another World, Vol. 4 is where Ennki Hakari meets our catalogue, mid-run in a sequence that has plainly found and kept its audience.
The title carries the premise on its own: a knight in skeletal form, and a world other than the one the story began in. That displacement is the founding move of the isekai form, and our shelving reflects how hybrid the genre has become, with fantasy, science fiction and general fiction each laying a claim to it.