There are at least 3 artists known as Mayu:

1) 真優, a Japanese electronica singer, full name Mayu Kawata.

2) An American born singer/songwriter who writes songs in both English and Japanese.

3) MAYU, a Japanese VOCALOID developed and distributed by EXIT TUNES, released in December 2012 for the VOCALOID3 engine. Her voice provider has never been revealed. Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.