[1] Ai no Dai 6 Kan contains three hit singles, all released prior to the album between April and December 2004: "Roman: My Dear Boy", "Joshi Kashimashi Monogatari", and "Namida ga Tomaranai Hōkago".

Ai Kago and Nozomi Tsuji (who graduated from the group in August 2004 to continue with their duo W (Double You) full-time) perform along with the other 12 members of the group at the time on the first two aforementioned tracks, recorded and released as singles when they were a part of the group, and on "Ship To The Future", a song from Morning Musume's Spring 2004 Musical Help!!

Atchii Chikyu o Samasunda; a slower version of the latter was recorded by band members Rika Ishikawa and Sayumi Michishige under the name Ecomoni and released on the compilation Petit Best 5.

Ai no Dai 6 Kan is also Mari Yaguchi's last album with the group, although she continues to work as a general entertainer under the Hello!

and featuring some different lyrics as well as new vocals by the post-Mari Yaguchi lineup, is the title track of Morning Musume's 28th single release.