It's the second season of Puchimas! Petit Idolmaster, but I couldn't find the first one. I watched this anyway, though. You don't need to have watched Season 1 to follow the plot, you see, because there isn't one. It's a short-form comedy spin-off of THE iDOLM@STER, in which the girls of 765 Production are being followed around by tiny, semi-sentient versions of themselves. These are called Puchimas. They're broadly similar to their human counterparts in personality and colouring, but they're about the size of your head, they talk in incomprehensible squeaks and they have magical powers.
HARUKASAN (counterpart of Haruka) - is a Gremlin. She'll multiply when she gets wet, she can't stand bright sunlight and she turns evil if you feed her after midnight. Later, though, we learn that she has other powers too. If you ever see a ten-foot-high disembodied head, that'll be Harukasan. (About 80% of a Puchimas is its head.)
YAYO (counterpart of Yayoi) - grows bamboo shoots from the top of her head in the spring.
PIYO PIYO (counterpart of Kotori) - can fly.
MIURASAN (counterpart of Azusa Miura) - is liable to teleport to a random location if surprised... and take anyone nearby with her.
IO (counterpart of Iori) - can fire laser beams from her forehead. In ep.6, she has a Rapid Fire Mode.
CHIBIKI (counterpart of Hibiki) - if she gets scared or starts crying, she'll summon animals.
These are a bit surreal, but also usually irrelevant. Sometimes the Puchimas don't appear at all, in fact, and it's all about the human characters. They're all here too, although the Producer now has a giant "P" for a head. (In ep.68, we learn that he can pull on a human face on top of it. Is it a rubber mask?)
In fact, everything about the show is usually irrelevant. These are two-minute episodes! 2:20, to be precise, but fifty seconds of that will be the end credits and the "next episode" preview. You can't do much in ninety seconds. There will be cuteness. There will be silly things going on. There will be character interaction that almost never manages to be funny, but is at least warm and relaxing in a light-hearted way. However there won't be an ending. An average episode will be gentle and vaguely amusing until it stops, in a faintly puzzling way that makes you wonder what the point was. It's the kind of ending to make you think "that episode could have been good if they'd given it an ending."
I'm slightly reluctant to admit that these episodes should even be called episodes. They're episoids. They're little blobs of amusing cuteness in the approximate shape of episodes. It's as if THE iDOLM@STER sneezed.
That said, though, I've just watched all 74 of the buggers. It wasn't hard work, either. I enjoyed it. They're very watchable. It's easy to put on another two minutes of cute and mildly surreal fluff, although it would help to be familiar with THE iDOLM@STER's characters. This is ostensibly based in that world (albeit a silly fantasy version of it) and there's precious little room for character establishment or explaining who everyone is.
The episode length occasionally varies. Ep.45 is seven minutes long, while I think ep.65 is the shortest at 1:20. The latter still has the usual ninety seconds' worth of end credits and preview, by the way.
I quite liked it. It's a puzzling experience for a while, as your brain tries to interpret the show as ordinary television. Its episodes keep refusing to be anything you can process as episodes. However you'll soon get over that inconvenient perception and develop Stockholm Syndrome. Is the show ever actually good? Well, sort of. The Puchimas themselves are genuinely cute in human-free episodes, busily doing eccentric things while having fhofghouuversations with each other in pure whuhuhwuhwbabble. Their surrealism can also be funny, e.g. Haruksan eating phones. Occasionally, by accident, the show might even burp up something I'd recognise as a well-constructed (if short) episode. Ep.5 and ep.33 spring to mind.
I'm not an unbiased judge because I'm a fan of THE iDOLM@STER, but this show made me smile. Sometimes it even made me laugh, e.g. dozy Miurasan nearly getting herself eaten in ep.34. Sometimes I'd be laughing just at a mildly surreal visual, e.g. fishing for Puchimas in ep.60. Half of my reason for watching was probably my fondness for the closing title sequences, though. (#1 is great, #2 grew on me and #3 is okay.) To my surprise, I'd almost recommend this.