CHARCOAL FILTER was a Japanese pop rock band. The members were Otsuka (vocals), Kona (guitar), Yasui (bass) and Takano (drums). After releasing a 1,000 copy indie album and several unsucessful singles, the group first made it big when their single "Tightrope" was selected as the ending theme song for the Gensoumaden Saiyuki anime series. After that, the group released several full-length and mini-albums, a "best" album, and a DVD collection of promotional videos with commentary.
In 2006, the band signed to Nippon Crown and released mini-albim "?????" and "Gimme a Light 2" (the latter as a tribute to their first mini-album, "Gimme a Light"). In early 2007, they released the album "Everything you know is wrong." Shortly after this release, in July 2007, CHARCOAL FILTER announced their disbandment. The very final mini-album, "????????", comprised four songs written by the four members respectively, and two songs written by the whole band.