the kamaboko squad, rengoku and shinobu were on a mission until they got hit by a blood demon art, teleporting them to another universe or... FNAF

Shinobu: points at the abandoned Freddy Fazbear's

Zenitsu: AHHHHHHHHH, TANJIRO PROTECT MEEEEE I'M GONNA DIEEEE

Inosuke: THE KING OF THE MOUNTAINS CAN OVERCOME ANY CHALLENGE!! COME ON LET'S GOOOO

Tanjiro: INOSUKE WAIT- runs after him

Rengoku: COME ON KOCHO, LET'S GO!!

Shinobu: goes after them and they enter Freddy Fazbear's