One of the songs has a bit of Satori's theme in it, but that's really it as far as I know.

Originally posted by Cyalide:

I will buy it even if she only has 1 line of dialogue otherwise.... eh I might still but It won't be immediate

Bit late but short answer is no, at least no physical appearances. She's referenced in some dialogue and descriptions as Koishi's manager and that's all. She does appear in the physical exclusive soundtrack booklet for Rose Idol, but that's not even on Steam.

I'm gonna cry ;-;