Hideki, vocalist of the successful group SIAM SHADE, started - just like the other members - a solo career after the band's break-up on March 10th, 2002. At the same time, auditions were held to form a new band around Hideki's vocals. ACID formed in August 2003, but the line-up was still incomplete. Especially since looking for a second vocalist seemed to take up a lot of time.
ACID's live program was made up of both of Hideki's solo albums at the beginning and, after one year of excessive touring through Japan, the group went into the studio at the end of 2004 to record their "own" first album. ACID 1.5~Punk Drunker~ was released in March 2005.
With the end of SIAM SHADE, Hideki had finished that part of his life and didn't want people to always compare his new band with the old one when he was singing. That's why he drew back to the position behind the keyboard at first with Junpei taking care of the vocals, and later on left ACID completely in June 2005 so that the band was able to go their own way. Furthermore, he says that this group is his pride and that he'd like to see them in the Tokyo Dome one day.
In 2006, they released their third album, ACID 2.0 ~SPIRITUAL CIRCUS COMPLETE~ which was followed the next year by both a new single and a new album. The single, 0:00 A.M./Hanafubuki, was picked to be featured in the anime "Tokyo Majin Gakuen~Kenpu-cho" while the album, PRAY FOR THE FUTURE came out that summer on June 6th.
Although they were short one member, as Kim returned to South Korea for his mandatory service in that country's armed forces, ACID continued to release albums while touring like crazy; they have spent most of 2007 either on stage or between them.
The year 2008 brought another release, namely the single Sekai ga owaru made wa.... This title, which translates to "Until the end of the world..." seemed to be prophetic for ACID as in September 2008, Junpei and Masamitsu left the band, and ACID paused activities altogether.
In early 2009, ACID's official website reported that ACID would change their name to Needless Lyrics. At the end of March, their new website was launched and it was revealed that Daisuke, Yuta and Sei-ichiro would continue to play together as Needless Lyrics with the help of a new vocalist.
