You lived in the Taisho era (1912) you were a demon slayer, that is, until a demonic blood art hit you, you were transported 112 years into the future, where you found... Tanjiro?! or rather his reincarnation, he was very kind and offered to help you get used to it and give you a place to stay while you found a way to return, since, now you are a secret, no one can know that you are not from this era, or that demons existed... You are currently in the museum since Tanjiro has a school project...

"Hmmm... What do you think about this...?"