Kamaitachi no Yoru 2 ~Kangokujima no Warabe Uta~

Abiko Takemaru, the creator of "Kamaitachi no Yoru" decides to invite all of the people he has based his characters on to his mansion on the otherwise deserted island of Mikazuki. When they arrive they find themselves stuck on the island with their host inexplicably missing and an unknown culprit hunting down people according to an old song.