The duo would release one more single while retaining their earlier cute image, "Ai no Imi wo Oshiete!". Their following single, "Miss Love Tantei", would see the pair utilizing a more mature look and sound.
Another track, "Da-bu-ru-yuu Joshi Koutou Gakkou Kouka", is the mock-theme song for the fictional "Dabaruyuu Girls Senior School" (The nonsense word "Dabaruyuu" being a corruption of the duo's name) and ties in with the album cover concept depicting Kago and Tsuji at a school ceremony.
Many of the songs on the album, both originals and covers, center around the topic of becoming, or about to no longer be, the age of seventeen. At the time of the album's release, Ai Kago had turned 17 a month prior, while Nozomi Tsuji would turn 18 that June.
Unlike their first album Duo U&U, which was all cover material, 2nd W contains a mix of both originals (composed by mentor and Hello! Project founder Tsunku) and covers of classic Shōwa period female pop duo songs. Three of the songs, the Tsunku originals "Ai Ii na!" and "Robo Kiss", and a cover of The Peanuts's "Koi No Fuga", were released as singles in the months prior to the album; the latter selection was also the single released in advance of the album.
2nd W is the second album by the Hello! Project duo, W, and the first to be recorded (except for one song) and released after its members, Ai Kago and Nozomi Tsuji, "graduated" from Morning Musume in August 2004.