The Great Jahy Will Not Be Defeated! (ジャヒー様はくじけない！,Jahy-sama wa Kujikenai!?, lit. Jahy-sama Won't Be Discouraged!) is a Japanese manga series written and illustrated by Wakame Konbu. It has been serializing since August 22, 2017 in Square Enix's Gangan JOKER.
An English-translated version of the manga has been licensed by the US branch of Square Enix Manga, and an anime adaptation has been announced as of April 16, 2021.
Puny and powerless after an unfortunate encounter with a magical girl, the Dark Realm's Number Two has her work cut out for her in the world of humans!
The Great Jahy, the Dark Realm's second-in-command, cuts a frightening figure, feared and revered by all. But when a run-in with a magical girl results in the destruction of the precious mana crystal, the Dark Realm falls, transporting the newly puny and powerless Jahy to the human world! Unfortunately, plotting the revival of the Dark Realm from a cramped, crumbling one-room apartment is no easy feat when you have rent to pay and a job to keep!