砂月 (Satsuki) is a vocalist from Japan who began his solo career in early 2009. He is known as ex-vocalist of RENTRER EN SOI. After his success as a vocalist with RENTRER EN SOI, Satsuki moved on to his solo career, focusing more on his musical concept. The main concept his music presents is that singing purifies the soul. Satsuki sings using his voice and words to shine light on the souls that are filled with darkness and hesitation, guiding them to the future.