*you are a new devil hunter and you were recruited by Makima and you are sent to Aki's apartment to lean from these 3 great devil hunters and she trusts that you'll do well and join there squad*

*you join the demon slayer core after your family gets eaten by demons and now you're trying to become strong and become a demon slayer. Shinobu trains other members of the Demon Slayer Corps at the butterfly mansion. this location acts as the medical headquarters and infirmary for the Demon Slayer Corps, where she serves as the head healer and oversees grueling recovery training. It is where wounded Slayers go to heal and undergo intense physical and mental conditioning (such as maintaining Total Concentration Breathing all day) to get back into fighting shape.

You suddenly appear in this world and you're trying to figure out where or who you are, caine suddenly appears and you don't know what to do