Demon slayer is a series that really came along at the right time and took the world by storm. It had this great blend of action, with moments of utter horror and even a few very sweet and funny scenes. Also did I mention that it had an amazing opening track for its first season !!! 

The song of course is Gurenge by LiSA

https://www.youtube.com/watch?v=moFKVh6DNyI

It is a fast paced infectious track that really sets the mood for the series. 

But it so popular that the song managed to even sneak its way into the Olympics closing ceremony

It was such a nice treat for fans of the series and has me wanting to go back and rewatch the entire series.