Area 11 are a four piece Gaijin rock band based in Bristol, England. Their lead singer and keytarist, Sparkles*, also works as the audio production manager at the YogTowers, the HQ for the popular YouTube channel "The Yogscast".
They pioneered their own unique "genre" dubbed Gaijin Rock, which translates to "Foreigner Rock" in Japanese. The idea is that the songs are influenced by Japanese art and music, with anime and manga references to go along with the eastern-inspired synth hooks and soaring vocals, while still being Western at it's core, with leading guitar and strong percussive beats.
Most of their songs are references directly or indirectly to different anime. The band got it's start when after a jam session, they all discovered they had a mutual love of anime, and they sat down and watched an episode of Code Geass, which inspired both the band's name, and their first song, "Euphemia".
Some other examples of this include "Vectors" which references Elfen Lied, "Shi No Barado" which references Death Note, and "Heaven-Piercing Giga Drill" which references Tengen Toppa Gurren Lagann.