Hatsune Miku is a popular Vocaloid. She is the human avatar of a vocal synthesizer whose voicebank (vocal database) was provided by Japanese voice actress Saki Fujita. Her name in Japanese means "the first sound from the future."
She has a large fandom following and is the most well-known Vocaloid.
Her first voicebank was released in 2007, and Miku was originally popular in her native Japan before reaching an international audience."