This one drops your blood pressure about twenty points. Makoto Kobayashi built What's Michael? on a single unfair advantage: he actually watched cats, so Michael the tabby sits, stretches, and refuses like a real animal even while the gags go completely stupid around him. The 1988 OVA runs on vignettes instead of plot, which means no arc to track and nothing at stake beyond whether the humans in Michael's orbit get through the afternoon with their dignity. All that late-80s cel work spent on feline body language rather than spectacle is the whole flex, and it lands. Put it on with anyone who has ever lost an argument to a housecat, and watch how fast they start narrating along.
What's Michael? 2 is a 1988 comedy OVA.