It was released by Cube Entertainment on October 14, 2009 and contains five songs, including the singles "Bad Girl" and "Mystery".

The song "Yet" (아직은, Ajigeun) was banned from airplay due to (believed) swearing in JunHyung's rap.

[6] In early 2010, Beast promoted their second single, "Mystery", from the mini-album, with live performances on the weekly music shows.

[7] On February 14, 2012, Beast's official YouTube channel uploaded a special music video for "Mystery".

On November 11, 2009, Korean broadcaster KBS banned the playing of the song "Ajigeun" because of a phrase that had the potential to be misheard and misunderstood as an offensive word.