Cells At Work (aka Hataraku Saibou) is a surprisingly charming show about the moe anthropomorphised cells in the human body. Whoever that human is had better be grateful for such an efficient immune and blood system because they surely need it with all the trouble they get into.
Watching Cells at Work is one of the most blatantly educational experiences I’ve ever had in anime but somehow manages to make this part of the fun. The show is regularly interrupted by a voiceover explaining just what has gone wrong with the hapless human this time, and/or to explain how our heroic cells will be dealing with the problem.
To facilitate the story moving all over the place, the main character Red Blood Cell (AE3803) basically has Ryouga’s sense of direction from Ranma ½. This is somewhat mitigated by the facts that she can’t actually leave the body or (for the most part) the blood vessels, and the valves prevent her travelling in entirely the wrong direction.
But leaving those constraints aside: Ryouga and Red Blood Cell must never be allowed to meet.
It does mean that the writers have a convenient excuse for Red Blood Cell to always be where the latest disaster is. As for the other main character, White Blood Cell (U-1146) being where the disasters is actually what he’s supposed to do, so that’s generally easier to explain.
There’s a huge range of other characters ranging from funny to creepily disturbing that Red Blood Cell interacts with over the course of the series.
No review of Cells at Work is complete without mentioning the Platelets. The entire series is built on moe anthropomorphism, but the Platelets are the weapons grade version that approaches the Cute Event Horizon. When looked at in that way I suppose it’s just as well that they never got enough screen time to satisfy everyone.
One thing that the show doesn’t shy away from is that some issues require external support for the body to fix. Episode 11 Heat Stroke is ultimately resolved by an intravenous drip restoring fluids to the body, and episodes 12/13 Hemorrhagic Shock are resolved by a blood transfusion.
The latter is hilariously done because the transfused blood cells are initially disoriented and also speak in a distinctly different accent. After all, they come from another world so of course they have a different accent.
Overall, Cells at Work is a fun, educational show that stacks up surprisingly well against real scrutiny. This video by Dr Hope’s Sick Notes is also a lot of fun (and he’s since done one for episode 2):
Here’s the OP:
 According to Wikipedia one of the manga chapters we didn’t get is Dengue Fever…
 These voiceovers are usually Kikuko Inoue as Macrophage (if I recognised the voce correctly).
 The voiceover includes which cells are dealing with the problem, and how they are different.
 She wears a badge with the number on it.
 The Macrophages are essentially elegant, gentle, serial killer maids with large dresses and bigger axes who somehow go incognito in Hazmat suits as Monocytes whilst in the blood vessels. And that sentence makes perfect sense to anyone who’s seen episode 10 Staphylococcus aureus.