The entire series is a Show Within a Show in the main iDOLM@STER universe.
At some point, 765 Production teamed up with an animation company to create a tie-in anime a la AKB0048. This would explain not only the complete Genre Shift, but also why they have a completely different cast from the games and the eventual anime adaptations. And like I said with the AKB0048 comparison, anime to promote real life isn't that uncommon...at least at the time, nowadays it's vice-versa. Not to say that iDOLM@STER isn't, but I mean in the context In-Universe.- I'm not opposed to this idea, but in-universe, it was likely made before the events of the A1 Pictures TV show, considering the absence of Takane and Hibiki (as they did not join 765 Pro until Dearly Stars).
