Mukashi Yuusha de Ima wa Hone / Скелет, который был храбрецом

Alvis, the hero, lost his life in a battle with the Demon King. However, he lived on... as a skeleton!? Ending his career as the hero who defeated the Demon King, he spent 3 years sleeping, playing and enjoying every day. However, in order to find his long-time friend Izana, he once again enrolls as an adventurer, and changes his name from Alvis to Al the Skeleton. Due to his appearance being that of a skeleton, trouble is not out of the question for his near future! Protecting traveling merchants, mapping unexplored dungeons and so on; while undertaking numerous requests, Al the Skeleton wields his sword another day in order to save lives.

(Source: Tokuma Shoten, translated)