My insatiable hunger for Idolm@ster videos led me from Youtube to Nico, where I found this fan edition:

The chick represents Kotori, the non-playable character. She is an office assistant in the 765 Studios. On the Master of Master CD, she does the Talk 02 track and "is made by audience" to sing, delivers sora, and is every bit as good as any regular employee whose job is actually to sing (CV: Juri Takita). I wonder if it's a hint at goings on in Rondo-robe.

Finding what she actually looks like requires a few searches. The official site only has a smallish sprite (center). She also appears in promotional materials (left), and in figure set (right).

The only in-game screen I have is this:

It may or may not be real. Kotori says "タベ、危ない目にあってる私を、真ちゃんが助けてくれる......、夢を見たんです。うふふ......", which is a perfect case of "know all words, cannot understand the meaning" for me. Someone has a dangerous eye, and then she saw a dream? In which Makoto saved her? Particles!

Anyway, after seeing the website "Kotorim@ster", I have to suspect that a part of Kotori's popularity has something to do with the office space romance.

Prosecution rests the case.

UPDATE: J.Greely e-mailed:

危ない目に会う is "to be exposed to danger; to have a dangerous experience"; I had to use my big dictionary to find it.

Now it all makes complete sense: Kotori saw a dream where Makoto rescued her.