This isn't the 2018 Netflix series. That's season two. This is the original that you're much less likely to have heard of, made of micro-episodes that were broadcast on TBS Television. The shows are basically the same, though, although the Netflix one has longer episodes and hence can have some plot.
It's set in a world of talking animals, animated in Flash by the people who brought you Hello Kitty. They're really just people, though. They go to work every day, bitch, annoy each other, wish they had a boyfriend and demonstrate all the ways in which life at work is hell. Our heroine, Retsuko, is a hard-working red panda. She understands how Japanese office life works, which means she's polite, self-effacing and an expert at knowing what you want without you saying it. Unfortunately her friends and colleagues are a bunch of selfish, thoughtless narcissists who... no, that's not quite right. They're people. They do all the annoying things people do.
When they annoy Retsuko, she sings Death Metal. (She has two voice actors, incidentally, playing respectively Normal!Retsuko and Metal!Retsuko. The latter in Japanese is almost incomprehensible and is also the show's writer/director.) After she's finished singing, though, Retsuko will return to her usual meek self and do whatever's required by good manners.
This is pretty funny. The show's a lot more clever and watchable than you'd expect of one-minute episodes, although I'd advise against trying to marathon it. (There's no room for any plot, so watching too many episodes at once will go a bit non sequitur.) It's funny because it's true. These aren't bad people... well, except for Ton the Pig Boss, who deserves to get turned into bacon. They're just doing ordinary-but-annoying things in a show that has a laser focus on identifying and skewering them. Tsunoda's just your average self-absorbed "I'm So Pretty" girl who's always dressed to perfection and has huge girlie eyes. Buffalo Boss seems like quite a good boss (at least compared with Ton), but then you realise how needy and shameless he is. Plenty of the cast aren't even that bad, being perfectly nice people who just happen to have these little habits and assumptions.
Besides, sometimes Aggretsuko's rage is directed more at the world. The Valentine's Day shopping episode made me laugh. It's a warzone out there.
This show's definitely worth a look. They're only one-minute episodes! What have you got to lose? Don't binge them, but they're engaging if you just watch a few here and there. You'll recognise Retsuko if you've ever wanted to paint your face like Gene Simmons and scream about something very very small. She's got a boss who'll shove all his work on you just before going-home time (and you'll have to stay late and do it), while accusing you of being a gold-digger who's planning to quit anyway. She'll acquire a junior assistant who's so noisily humble and obedient that it's not clear he has a brain. She needs to calm down a bit, but you can see what she means. I'm looking forward to seeing how the Netflix show compares.