僕がモンスターになった日 (Boku ga Monster ni Natta Hi)

Background
"The day I became a Monster" is an original song by rerulili featuring Fukase. This song is an official demonstration song for the VOCALOID4 Library Fukase.

The song is mainly about Fukase, who was once a normal boy, turning into the look we know today. (Which is referred as 'monster')

This is rerulili's 42nd original work.

This song is featured in the Fukase compilation album, VOCALOID Fukase ~THE GREATEST HITS~, and the rerulili album Seishun Shokougun.

This song has entered the Hall of Fame and has exceeded over 100,000 views on YouTube.