Wow dont just kill her her granny like she. Shes still alive right here
Granny was never in Gunma when it fell as stated by Kinoko saying only her, her sister, and gramps was there
alas gramps has already left the world so he may have been a former #1 high ranker who's rank disappeared when he died, with Kinoko replacing him. this is because his training regime for Kinoko still required the defeat of 4 S rank creatures daily even if not the absurd amount Kinono was doing that hunted them to extinction. He still raised her and trained her in such a harsh environment before passing