Information:
These three voice actresses collaborated to perform the ending theme song to "Gargoyle of the Yoshinagas" or "Yoshinaga sanchi no Gargoyle" (they voiced Yoshinaga Futaba, Riri Hamilton, and Onodera Mimori respectively). Each of them are well known voice actresses in their own right, and Mizuki Nana is best known
for her performance of various anime theme songs (she is the daughter of famous anime song performer Mizuki
Ichirou). Here is a partial list of each of their noteable works:

Saitou - Hinata Natsumi (Keroro Gunsou), Lavie Head (Last Exile), Louise Halevy (Mobile Suit Gundam 00).

Mizuki - Wrath (Fullmetal Alchemist), Rokumatsuri Minazuki (Happy Lesson), Minamito Yui (Ichigo 100%), Hyuuga Hinata (Naruto series).

Inamura - Sasagawa Kyouko (Katekyo Hitman Reborn!)