Saya no Uta
is a Lovecraftian horror visual novel by Nitroplus with erotic content. The original plot was written by Gen Urobuchi. In 2009, an English fan translation patch was released. Later, in 2013, JAST USA released an English localization using an improved version of the fan translation.
A three-issue comic book based on Saya no Uta, called Song of Saya, has been produced by IDW Publishing. The issues were released from February though April 2010.
A feature film adaptation is currently being developed by Sav! The World Productions.