: This is the original source material written by Shinta Fuji and illustrated by Susumu Kuroi , with six volumes published under the MF Books imprint. Collectible Paper Goods
The most common "good paper" items are the official physical volumes. Ningen Fushin no Boukensha tachi ga Sekai o Suk...
: While often made of tinplate, manufacturers like Contents Seed produce character badges that are frequently packaged with high-quality cardstock backing. Go to product viewer dialog for this item. : This is the original source material written
For collectors, various retailers offer official paper-based merchandise: Ningen Fushin no Boukensha tachi ga Sekai o Suk...
It sounds like you're looking for high-quality paper goods or the manga/light novel for ( Apparently, Disillusioned Adventurers Will Save the World ).