The act of a VTuber starting their career by making an introductory video or stream. See debut (noun).
▸ "The art of debuting has definitely become a staple in VTuber culture."
▸ "There's no one way to debut, but there is a way that only you can do."
▸ "You can debut and re-debut as many times as you'd like; though most VTubers only do it once."