WATCH: Hatsune Miku, Japanese Animated "Humanoid" Performs 'Sharing the World' on 'Letterman'

The live musical act at the end of every Late Show with David Letterman is always a staple of the nightly variety show, but last night the performer was only semi-there. Introuducing, Hatsune Miku, an animated Japanese pop star who made her American TV debut last night (Oct. 8) on Letterman with a performance of "Sharing the World" that left the talk show host a little bit confused.

Miku, a "humanoid persona" is a highly popular anime character, emerging from a voice synthesizer and a Japanese video game. So, unlike fellow animated musical acts like Gorillaz, there's no actual person behind the music of Hatsune Miku... she's all computer technology and fan interaction.

Despite the fact that Miku isn't, you know, real, she and her music have become insanely popular around the world. She opened up for Lady Gaga's ArtRave Tour during its first month, for instance. And now, she's coming for the U.S.

Alongside a living, breathing backing band Miku performed one of her singles "Sharing the World." Despite being a projection on a television screen, Miku was, well, animated, moving around and waving her arms, attempting to get the mildly confused American audience interested in her performance.

After the song, Letterman approached the band and seemed a little confused by it all, likening the experience to one of music's more trippy acts.

"It's like being on Willie Nelson's bus," he said after Miku instantly disappeared from the set.

Not quite, but we get what he's saying...

Watch the Hatsune Miku performance of "Sharing the World" below: