Bassist Akihiro Yokoyama joined in 1983, held de facto leadership of the group from 1988, and appeared on every recording the band had until his death in 2014.
Originally a Judas Priest and Black Sabbath cover band, they began to write their own material in 1983 when bassist Yokoyama joined.
They have played with Anthrax, Slayer, Testament and Machine Head on their Japanese tours, and in 2010 was Paul Di'Anno's live band for his.
The band's longest serving member, bassist and manager Akihiro Yokoyama, died on May 13, 2014.
[6] A concert titled Yoko Fest The Final was held in his honor on September 12, 2014, that featured nearly every member of United, past and present, and other diverse acts such as Head Phones President, Passpo, Garlic Boys, Flow, and Outrage.