Dungeon Elf: Dungeon ni Takarabako ga Aru no wa Atarimae desu ka?

A mystery that not even the most devoted RPG enthusiast can explain.
How are there all these conveniently placed treasure chests in the dungeons?
From the grassy glade in the beginner's forest, to the most perilous depths, where even heroes must face the possibility of total annihilation, and sometimes even within ordinary homes. The treasure chests are always there, aiding the adventurers and maintaining the balance of the world. This is the untold, unappreciated tale of the one who carries the treasure chests.

(Source: Comic Days, translated)