Grimgar of Fantasy and Ash (灰と幻想のグリムガル, Hai to Gensō no Gurimugaru) is a Japanese light novel series written by Ao Jūmonji and illustrated by Eiri Shirai.

The story follows a group of people who suddenly find themselves in a fantasy world with no memories from before their arrival, and chronicles their struggles to survive and make a life for themselves as volunteer soldiers.

It is revealed through a flashback that the party, which likely originates from modern Earth, awoke with a large group of people on this world just a few weeks ago.

With no memory of how they arrived and no other options they are quickly pressed into service as Trainee Volunteer Soldiers by a mysterious individual named Chief Britney.

Led by a man named Manato they have banded together, joined class guilds, and begun hunting weak monsters as a way to grow stronger and earn the money they need to survive.

Eventually, the party learns to work as a unit and experiences enough success hunting goblins to move from the forest to a ruined city.

A manga adaptation by Mutsumi Okubashi was serialized in Square Enix's magazine Gangan Joker from 22 April 2015 to 22 June 2016 and collected in three volumes.