The iDOLM@STER Prologue SideM: Episode of Jupiter

After leaving 961 Production, Touma Amagase, Shouta Mitarai, and Hokuto Ijuuin continue performing as Jupiter on their own terms. Their popularity is growing, but without the machinery of a major agency behind them, even successful concerts require exhausting effort and help from volunteers.

Takashi Saito of the newly formed 315 Production repeatedly offers to represent them, but past experience makes the trio wary of another producer's promises. As Jupiter considers what independence really means, they are forced to remember that their choices affect not only themselves but also the fans who continue waiting for them.