Hidekazu Koyama, alternatively known as a vocaloid producer under the names Nanou, Hoehoe-P and Getsumen, is a Japanese vocalist, lyricist, composer, arranger, guitarist and member of the rock band CIVILIAN. As a vocaloid producer, he has created both covers and original songs, where he mainly used the vocaloid Hatsune Miku. Additionally, many of his original songs have entered the Nico Nico Douga Hall of Fame. He also used to cover songs as an utaite.