Work conditions are just as awful as ever for the cells of the body in the fourth volume of Cells at Work! Code Black, but one red blood cell tries to remain optimistic. Might be a bit of a misplaced attitude to have, particularly with the body doing no favours for itself.
This volume of the manga contains chapters eighteen through to twenty-four.

Front cover of the fourth volume of Cells at Work! Code Black, featuring the white blood cells
SUGAR, SUGAR
The red blood cells have a problem on their hands when their customers start refusing their sugar deliveries! The pancreas hasn’t been producing enough insulin, and without it, sugar just keeps accumulating in the body and causing problems for every cell along the way! The red blood cells travel to the pancreas to set things right, but what they find there is a situation more hopeless than they could have imagined… one that could spell doom for them all! Will these determined cells be able to save their new home?
This particular volume of Cells at Work! Code Black shows the harm that diabetes can do to the body, and it really is not pretty for the cells. They all get caught up in it in some way, as the lead Red Blood Cell of this series discovers.
Even with everything seemingly falling part, he remains as determined as ever that the body will get better – with the cells’ help, of course.
We also get a few chapters that focus on the white blood cells, particularly how one can’t bring herself to accept the aid of another who came from outside. Of course, they also have their work cut out fighting off bacteria and such, but not even they can prevent some pretty terrible things from happening.
Those events do lead to the native White Blood Cell realising some things, though at great cost.
Another thing this volume demonstrates is that a variety of factors result in certain cells no longer having a job to do. There is little else for them to do but accept that, though their thoughts and feelings do help Red Blood Cell gain some perspective about this new body he finds himself working in.
This volume ends on a cliffhanger, and a dark one at that. Things look really bleak for the body.
Still, seeing the cells face all a manner of struggles does make for some pretty interesting reading. The mature rating this manga has also means that it can explore some really dark themes more freely. That certainly fits with the whole “edgy” version of Cells at Work! that Code Black has going on.
An enjoyable enough read, but anyone who prefers to think of Cells at Work! as a more cutesy work (probably due to the Platelets) might find this a little too much.