The Ways of the Monster Nation

That Time I Got Reincarnated as a Slime: The Ways of the Monster Nation (転生したらスライムだった件～魔物の国の歩き方～) or A Travel Guide to the Land of Monsters is a side story manga by Shō Okagiri. The series is held chronologically after the Founding the Demon Capital Arc but before the Devil's Secret Maneuvers Arc or around Light Novel Volume 9 - Light Novel Volume 10. It explores how the Monster Country Tempest works and thrives through the eyes of the Rabbitman (Lycanthrope) Flavia as she is given special privileges for being hired by Rimuru to test out and rate/review various aspects of the country in hopes of giving the public an honest advertisement from a consumer's point of view. The series has been serialized on Micro Magazine's Comic Ride website since July 28, 2016. The first volume was released on April 7, 2017. Yen Press announced it has licensed the series on January 6, 2020. The first English volume will be released in June 2020.

Synopsis
The Jura-Tempest Federation is finally making waves in the wider world around them. Their leader decides it’s time to compile a Tempest guidebook—and there’s no one better for the job than a local rabbitfolk girl! Follow her adventures in this unique spin-off, out June 2020!

Translation Notes

 * Alternate Translations include "The Ways of Strolling in the Demon Country," "How Monsters Walk" and "How the Monster Country Works," it actually refers to how the Monster Country Tempest is thriving and advancing. In other words, how Tempest works/functions as a country.
 * The breakdown of the title is "Monsters'" (魔物の Mamono no) "Country's" (国の Kuni no) "Way/Method of Walking" (歩き方 Arukikata) referring to how it "works/thrives/advances/progresses." In other words, "How the Monster Country Works."