Who are you?

A white, skeletal character in a blue hoodie stands with a smug expression as the text "WHO ARE YOU?" appears, then the scene shifts to the character standing atop a large skull with smaller skulls floating around, followed by a close-up of the character's face with a determined expression, then a girl with brown and pink hair stands still, then a pink laser beam shoots across the screen, and finally a character with a white bob haircut holds a small object while a ghostly figure appears behind them.