Akagumi 4 was one of the original Hello! Project shuffle units in 2000 along with Kiiro 5 and Aoiro 7. The group was led by Nakazawa Yuko. Their song was Akai Nikkichou (Red Diary). The song was released on 8cm CD single (EPDE-1073), and was also released on the first Pucchi Best (Petit Best) album, subtitled The Ki Ao Aka.
After Danielle's graduation, Maeda Yuki took her lines and Yoshizawa Hitomi took Shinoda's, forming the temporary 2nd Generation.
Akai Nikkichou was covered by Goto Maki on her album Makking Gold 1 and by Nakazawa Yuko on the Together! album. Nakazawa's version has the English opening speech rewritten into Japanese, while Goto's version doesn't include either speech.