Calliope Mori is a virtual YouTuber and a member of Hololive English, part of the first generation known as 'HoloMyth.' She is depicted as the Grim Reaper's first apprentice, and she often incorporates the theme of death in her persona and content. Calliope is known for her musical talent, particularly in rapping, and has released several original songs and albums. With her charming and laid-back personality, she engages with her audience through live streams, gaming sessions, and music performances, making her a beloved figure in the Hololive community.