Do As Infinity (Japanese: ドゥー・アズ・インフィニティ or Chinese: 大無限樂團) is a J-Rock group on the avex trax label. They are named after composer and creator, Nagao Dai, who no longer has an active role in the public face of the group, despite originally appearing at public events and in their promotional videos alongside Van Tomiko and Owatari Ryo. These days he remains in the background and only occassionally makes appearances at concerts. The DAI acronym can also be attributed to the Japanese word meaning "great".
The group debuted on September 29, 1999 with Tangerine Dream and holding a free concert in Shibuya. Their songs Fukai Mori and Shinjitsu no Uta were both used as theme songs for the anime Inuyasha, and Rakuen was used as the main theme for the anime's fourth movie, in which both Ryo and Tomiko had small guest voice acting roles.
Their unique mix of samples and electric guitar solos, accompanied with acoustic guitars, alongside Tomiko's unique style of singing gave them their own distinct sound.
On September 13, 2005, Do As Infinity officially announced that they would disband on September 29, on their sixth year anniversary. They released their 2-disc single compilation album Do The A-Side at that time. They reformed only once on November 25, 2005, for the Do As Infinity -Final- concert, where Van Tomiko and Owatari Ryo were joined by Nagao Dai.
By the end of their career, Do As Infinity had released six full albums and twenty singles. Owatari Ryo now works with his band Missile Innovation, and Van Tomiko is pursuing a solo singing career.