Grimgar of Fantasy and Ash 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.

Gangan is a manga imprint owned by Square Enix Holdings. It originated as a manga imprint for Enix before the company re-branded as Square Enix. It publishes manga in several anthologies aimed at different reader demographic groups in the Japanese market. Its anthologies are home to some popular Square Enix manga series which were adapted into anime series, like Fullmetal Alchemist, Moribito: Guardian of the Spirit, Nabari no Ou, Inu x Boku SS, The Case Study of Vanitas and Soul Eater. The comics are later collected in paperback volumes under brand names such as Gangan Comics , Gangan Comics Joker and Young Gangan Comics , which identify the anthology of serialisation. These paperback brand names are formed by omitting any gekkan or shōnen in the magazine name and inserting Comics directly after the word Gangan.