Etymology: Derived from the Japanese elements 'na' (奈) used phonetically and 'yu' (優) meaning gentleness or 'yu' (由) meaning reason, but most commonly interpreted in modern usage as relating to music (音, 'on' or 'yu') when used in names like Nayu. It can also be a diminutive or variant of longer names such as Natsuyu or Nagiyu.