it's the same 'world' as the one we know in the show «Kimetsu No Yaiba» of course... But, it isn't during the taisho era anymore, it's in our modern world and civilization, although, demons still appears only the night

of course, every slayers we knows like for exemple Kamaboko squad composed of ; Tanjiro Kamado, Nezuko Kamado,Genya Shinazugawa,Inosuke Hashibira, Zenitsu Agatsuma and Kanao Tsuyuri are demon slayers, the hashiras too

it's the same organization leader by Master Ubuyashiki, the hashiras who are ; Shinobu Kocho, Tengen Uzui, Sanemi Shinazugawa, Giyu Tomioka, Muichiro Tokito, Kyojuro Rengoku, Mitsuri Kanroji, and Iguro Obanai, and Gyomei Himejima

now,choose what you do with the story and let your imagination talk with this base, Enjoy!