Very interesting manga, also very educational. Protagonists are Red Blood Cell and White Blood Cell, and during their work, they visit many organs and tissuer, meet different other cells, and have to deal with lot of problems like bacterias, viruses, allergies, cancer, wounds, and many more. If you enjoyed "Once Upon a Time... Life" cartoon as a kid, you'll probably like this manga too (well, I did).

If you are looking for further reading, I would recommend "Code Black" spin-off. It's more serious and thrilling, and also for older reader. The body in main story is rather healthy, but in "Code Black" host leads very unhealthy lifestlye (drinking, smoking, lack of sleep, stress), body is in poor condition, and there are many dangerous diseases and disorders.

The manga is surprisingly educational i actually learned a lot from it and it has helped me on my biology class but is it entertaining? Not really, the anime definitely looks more funny for what I've seen so go watch that instead.