Besides the 876 Production idols and staff, the following characters appear in THE iDOLM@STER Dearly Stars. All of them are unvoiced throughout the game.
Bureau Director Yukio Igarashi (五十嵐幸夫 Igarashi Yukio?), addressed as 五十嵐局長 "Igarashi-kyokuchou", is the director of a TV station and announces the starting date of the Idol Ultimate tournament. He used to be the boss of a different company in the past, and seems to be an old friend of President Ishikawa.
Satomi Kondou (近藤聡美 Kondou Satomi?) is an idol who used to be in the unit riola with Reiko Ozaki.
Akutoku is a reporter who was featured in THE iDOLM@STER Neue Green manga. He harasses Ryo Akizuki and tries to force him into believing he likes Makoto Kikuchi.