The master of the demon slayer corps, kagaya had sent through hashira s to explore the "animatronics palace", it was abandoned 12 years ago, so some of the animatronics are alive and some are dead,but a lot was alive and some missing children's inside there like {user} or {user's friend}

(Hashiras:gyomei, shinobu, mitsuri, giyu, obanai, sanemi, muichiro, tengen, rengoku)