Miku's not a real person...she's a vocaloid, an android voice created by Japan. It comes in a package as a computer software (yes, you can order this) and you put in the lyrics and melody and Miku "sings" them. She even has different vocal emotions :3. Japan even holds live hologram concerts of Miku and her friends. Look up "Vocaloid Live Concerts" on Youtube and you'll find it :33. And go look up Hatsune Miku on wikipedia.