ASIAN KUNG-FU GENERATION is a band that was first formed, as with most bands, when some guys (namely Masafumi Goto, Kensuke Kita, and Takahiro Yamada) meet at University and reckon they could start something together. Another guy (Kiyoshi Ijichi) tags along after his own band disperses and they start playing together. Only switch is that they are in Japan and they play at their resident Yokohama area and have been together since.

Having started out in 1996 and they only released they're first EP in 2000 with 6 tracks mostly sung in English. They started gaining popularity in 2001 when they sent their first single "konayuki" 粉 雪 to indie radio stations. It picked up slowly with help from a popular radio DJ on the station FM Yokohama. They released another EP around this period titled "I’m Standing Here" this time sung in Japanese.

They were rocking it independently for a while before being signed by Ki/oon Records キューンレコード and releasing the following albums (their indie flow and heart-felt lyrics not diminishing however, even at the face of fame);

The band members and their respective roles within the band are as follows:
  • Masafumi Gotō (後藤 正文, Gotō Masafumi?) – lead vocals, rhythm guitar
  • Kensuke Kita (喜多 建介, Kita Kensuke?) – lead guitar, backing vocals
  • Takahiro Yamada (山田 貴洋, Yamada Takahiro?) – bass, backing vocals
  • Kiyoshi Ijichi (伊地知 潔, Ijichi Kiyoshi?) – drums

Ajikan (as fans fondly call them) have had some songs on the openings of some popular anime, with ‘After Dark’ appearing in Bleach, ‘Haruka Kanata’ in Naruto and ‘Rewrite’ in Full Metal Alchemist. They also, according to a fan site, appear in an animated adventure/psychological drama film titled Tekkon Kinkurito.

These guys play a big part in my desire to keep learning nihongo especially when I don’t feel up to it- lazy bugger that I am.

I relied heavily on Wikipedia here – I’m a not-so-clued-up fan I’m afraid.
Also, thanks Aerobe for the bit about these guys' songs appearing in Anime.