In the beginning, the group was formed by Daisuke (the singer – although he had previously been the drummer for Fatima) and Masaya, ex Angel Dust. In October, they were joined by guitarist Yuana. Their first live took place at Ikebukuro Cyber in February 2000, during which a demotape was distributed. In the same year Shizumi, the drummer from 1m80, joined the group, but after the first oneman, Masaya decided to leave. He was replaced by Kuya in January 2001.

They joined the label Loop Ash. After that, their success grew and soon created their fan club, Tsushin Kouza on April 13th. In July of 2001, they held a oneman live for 1000 people at On Air East. It was at this time that Kuya decided to leave; he was replaced by Kazu from the group Aioria. Kagerou left their label afterwards.

In September they toured in Hong Kong with Due’le Quartz and Kagrra,. Their promising career continued, and in 2002 they released two maxi-singles - Iro megane to scandal and Hiaburi no kazoe uta along with a DVD. They released their first fill length album, simply titled Kagerou, in 2003.

The next year, a DVD and their next album, Rakushu, went on sale. In December, two new maxi-singles, Shiroi karasu and Kurokami, were released. 2005 was the beginning of the group’s establishment; they went to Europe three times! The first was in February, when they played onemans in Munich and Paris. The second was for the Rock Am Park and Rock Am Ring festivals, in North Germany. The third time was in October, for a coupling tour with DéspairsRay in Hamburg and Paris.

Between these tours, they released a maxi-single in March titled Zetsubou ni sayonara, followed in July by their third album Guroshoku. In November they released a new single, Kusatta umi de oborekaketeiru boku wo sukuttekureta kimi, in three versions, each with a hidden track. Kagerou went back to Europe in April 2006 for another tour, The abyssmal mind pierced by leucotome.
Unfortunately, they called it quits in 2007 and Daisuke started another band, the studs.