"Siren" (サイレン) is one of a series of four CDs single released with a first press where the whole item is made of a special type of paper, followed by a reissue. In the case of "Siren", the whole item is made of rice paper.
The simplicity and normal behaviour make Asian Kung-Fu Generation different from others Japanese bands. Their appearance on television is scarce and they are more concerned about their works than their image. Since the Fukushima's nuclear disaster, Asian Kung-Fu Generation is involved in favour of the definitive nuclear power stations shut down. Despite an agreement made with Ki/oon Records (Sony), the whole Asian Kung-Fu Generation's discography is financed by the band itself, allowing them to be musically independent towards the label.