Aldious - short for 'Ultimate Melodious -' is a Japanese power metal band based out of Osaka. Originally consisting of Yoshi, Rami, Ruki and Sawa, the band was formed in 2008. Ruki and Sawa soon quit and were replaced by Toki and Kaze, with whom the band released its debut EP Dear Slave. After the return of Sawa, the band formed its own record label Bright Star Records. It released its debut album Deep Exceed in 2010 and followed it up with its sophomore album Determination the very next year. A commercial success, the second album featured tracks such as the hit "Spirit Black," which was used as a theme song in a TV show. Despite continued success, co-founder and vocalist Rami withdrew from the group and Re:NO was roped in as the new frontwoman. Aldious' third album District Zero released in 2013 became its breakthrough album and helped the band enter the top ten charts. The band has continued its successful streak with its subsequent albums released over the years and is considered as one of Japan's leading girls metal bands.