Editing Do As Infinity (section)

===2000===
The next single, "[[Yesterday & Today (Do As Infinity song)|Yesterday & Today]]" was chosen as the theme song for the drama series ''Nisennen no Koi'',<ref>{{cite web|url=https://www.imdb.com/name/nm0619137/|title=Dai Nagao|work=[[Internet Movie Database]]|access-date=2007-12-30}}</ref> which starred popular actors [[Miho Nakayama]] and [[Kaneshiro Takeshi]] and was given the primetime slot. The c/w-track, "Raven", was used as the ending song to the horror movie ''[[Uzumaki (film)|Uzumaki]]'', which gathered more mainstream audiences for the band.

Their first album, ''[[Break of Dawn (Do As Infinity album)|Break of Dawn]]'', debuted on number three on the [[Oricon]] album charts in March of the same year, only a month after "Yesterday & Today". They continued to make public appearances and do numerous live performances all over Japan. In August of that year, the band released the single "[[Rumble Fish (song)|Rumble Fish]]", which was used as the theme song for the hit movie ''Kamen Gakuen''; the cover of "Rumble Fish" was taken in Taiwan, and the trip provided the inspiration for "Shinjitsu no Uta".<ref name="trivia"/> Also in August, the single "Summer Days" was released, which would go on to become a staple at all Do As Infinity live concerts, and was used as a theme song for Fuji TV's ''OL Police''. "Summer Days" is also notable for being Do As Infinity's most well-known all-[[English language|English]] song (following their first, "Break of Dawn", from their debut album). During November of that same year, the band released the festive single "We Are.", which Tomiko has often said is one of her favorite DAI songs. The band would end the year with another countdown live held at the Velfarre club in [[Roppongi]].

Nagao resigned as front member on New Year's Eve in 2000, and concentrated on composition thereafter. After that, Nagao appeared in front of their fans as a member only twice more—the performance of the third debut anniversary held in September 2002, and a guest appearance in the second encore of their last live concert held on November 25, 2005. Nagao decided to work behind the scenes as he was unable to manage both the production of music and the live performance and [[promotional campaign]]. Nagao only wrote songs after he stopped appearing in public, and he hardly participated in recording.