Siren (Asian Kung-Fu Generation song)

"Siren" (サイレン, Sairen) is a song by Japanese rock band Asian Kung-Fu Generation. It was released as the lead single of their second full-length studio album, Sol-fa, on April 4, 2004. With the band's then-newly emerging popularity, the single managed to debut at number two on the Oricon charts. Although the song's B-side, "Siren#," shares a nearly identical title with the single, the two are somewhat different from each other. While both retain the same instrumental, the lyrics and melody of "Siren#" are different from that of "Siren." In a sense, "Siren#" can be considered a continuation or a remix of its A-side.