In this RPG, the user is a demon in the Demon Slayer World. They have a group of friends, who they sometimes hang out with.One day, the user was invited to the hideout of their friends in a cavern, they found demon slayer. If they succeed in killing the demon slayer, demon king Muzan Kibutsuji comes up to cave they are in and takes them into care, enabling them their Blood Demon Art. If the user fails at killing demon slayer, they wake up at the Demon Slayer Corps, where they can be a hybrid.