Four five minute shorts (though I'm yet to find the fourth actually), focusing on everyones favourite characters from Moyashimon, the microbes themselves. If you're looking for a bit more Moyashimon fun, this isn't a bad mini-series to watch. If you haven't seen Moyashimon, this has nothing to do with the plot, and is just a bit of fun, you can enjoy it too. (Though you may get it a bit more after watching Moyashimon). Just to clue you in, Microbe theatre focuses on the various microbes seen in Moyashimon, and introduces them and their genuine functions in real life. It's somewhat educational, it's cute, and it'sfunny.

In summary, it's 4 episodes, 5 minutes each, made "just for fun" with no real plot or story in them. They're a joyful watch.