Whatever one feels about the Anthropomorphized Anatomy series Cells at Work! and its spinoffs, it's hard to deny that the series knows how to diversify. The Shōnen Edutainment manga has served as a launchpad for several different spinoffs targeted towards multiple demographics: shonen, shojo, seinen, and even josei. Apart from their educational leanings, however, all of these spinoffs share one major attribute: the series focuses on the lives and jobs of human cells.
Except this one.
As the name implies, Cells at Work: Bacteria! (Hataraku Saikin) is a shojo manga focusing on the lives of the various bacteria that colonize the various areas of the human body, be they pathogenic ("bad bacteria") or beneficial ("good bacteria"), or neutral ("opportunistic bacteria"). As they are the main characters, the bacteria are treated differently from the other titles in the franchise: rather than being alienesque shonen-manga villains or brutal, animalistic forces of nature, they're all recast as characters in a shojo manga: lots of plucky cute girls and brooding pretty boys abound. There's also a bit more nuance to the morality of the series: the good bacteria aren't always "right" and the bad bacteria aren't necessarily always "wrong." The series all but admits that there has to be a balance to keep everything in check.
Bacteria is written and illustrated by Haruyuki Yoshida, with an original concept by Cells at Work! creator Akane Shimizu. It ran in the Shōjo anthology Nakayoshi from May 2017 until July 2020. The manga has also been licensed for Western release by Kodansha Comics, and its English run started in July 2020.
A sequel, Cells at Work: Bacteria NEO, launched in February 2021.
Other Spin-Offs of Cells at Work! include Cells NOT at Work!, Cells at Work! CODE BLACK, Cells at Work and Friends!, Cells at Work: Platelets!, Cells at Work: Baby!, Cells at Work! Lady and Cells At Work! White Brigade.
Cells at Work: Bacteria! contains examples of the following tropes:
- Anti-Villain: The leader of the C. perfinigens bacteria falls into this territory, as he expresses concern over his human host's unbalanced diet (even though it's beneficial to his species) and even other bacteria whose best interests aren't in line with his, like the vitamin-producing E. coli. He even has the odd heroic moment where he makes it abundantly clear that his goal is not to harm the host, but to help his species prosper. See also Ineffectual Sympathetic Villain.
- Backup from Otherworld: A large number of dead Lactic-Acid Bacteria enter the intestine from the stomach...and proceed to give off chemicals that greatly bolster the Bifidum Army.
- Bittersweet Ending: The C. perfinigens leader sacrifices himself to save longum from getting hit by a antibiotic which result in his subordinate to take his place while taking care of his duplicate who was created from him.
- Card-Carrying Villain: The leader of the Clostridium perfingens bacteria makes no bones about his status as a "bad bacteria" or his intentions to expand his group's turf. That said, he's not necessarily completely evil...
- Deadly Gas: After the host body eats barely anything but meat for nearly a week straight, Clostridium and his gang of bad intestinal bacteria are able to produce a large amount of hydrogen sulfide gas (rotten egg-scented gas) to harm the good bacteria. This also ends up giving her (the host body) a severe case of foul-smelling flatulence.
- Disney Death: The C. perfingens leader pulls a Heroic Sacrifice in order to stop Salmonella. He gets better shortly afterward.
- Subverted however in the penultimate chapter when he was shot by an antibiotic to save longum
- Enemy Mine: When an enemy appears that threatens the host's life — say, Salmonella — the "good" Bifidum Army and the "bad" C. perfingens bacteria join forces to protect the host.
- Enfant Terrible: Salmonella is portrayed as a very powerful and cruel little boy, that tries to take over and kill the host body.
- Funny Foreigner: Though more "odd" funny than "ha-ha" funny, the natto bacteria are a bunch of weirdly dressed country bumpkins who hang around the stomach — much to the good bacteria's exasperation — not doing much of anything... until the bad bacteria attack, and the natto bacteria proceed to grant incredible power to the Bifidum Army...
- Gasshole: Considering how the primary setting of this spin-off is the host's intestines, it's not too surprising that she would be portrayed as having some notable digestive issues, such as flatulence and burping.
- Guys are Slobs: Downplayed and gender-inverted. The host body (a teenage girl in high school) doesn't seem to have any serious issues, but she does appear to care less about her diet. The good bacteria even question how a teenage girl could eat so much meat.
- Heroic Sacrifice: C. perfingens sacrifices himself to stop Salmonella. After all, if the human host dies then so will all the bacteria — good, bad, or neutral. The death doesn't stick, however. It does however played out in the penultimate chapter when C. perfingens saved B.Longum from getting hit by the antibiotic bullet.
- Ineffectual Sympathetic Villain: The C. perfingens crew, as well as a few other bad bacteria groups, are portrayed as this. No matter how much havoc they wreak on the body, good bacteria will always be there to stop them. They're also a generally goofy bunch.
- Meat Versus Veggies: The "good" Bifidum Army loves vegetables, but the "bad" C. perfingens bacteria eat meat. Chapter 1 tells us that the host body loves to eat meat as well, since one of the good bacteria mentions it's all she ate for the past week.
- Moral Pragmatist: The various groups of Opportunistic Bacteria fall squarely under this trope, as they have no real interest in the morality or motives of either the "good" or "bad" bacteria. Interestingly, neither the good nor the bad bacteria are under any illusions that the opportunists are their friends, nor do the opportunists try to hide their single motive: they will always side with whoever is winning because they don't want to die.
- The Narrator: In the only appearance by any of the original Cells at Work! gang, White Blood Cell U-1146 presents relevant biology facts via narration boxes throughout the series.
- Our Hero Is Dead: Happens with C. perfingen in the penultimate chapter.
- Painting the Medium: Bacteria!, a Shōjo series, takes place in a high school girl's body, so the bacteria's appearances are more stylish or elegant than the ones in the main book. Their home is also shown to have a Victorian aesthetic, and a character is shown using magic to perform their cellular duties.
- Post-Stress Overeating: Following a supposedly bad break-up, the host body has taken to eating more meat in general, which causes her to have varying levels of intestinal distress.
- Shout-Out: When the Clostridium perfingens leader finds out why the Bad-Bacteria colony suddenly shrinks, he puts on Conan Edogawa's glasses and bowtie.
- Taking the Bullet: This happens at the end of the penultimate chapter when C. perfingens saves B.Longum from getting hit by an antibiotic by letting it strike at him.
- Virtuous Vegetarianism: Enforced. The Bifidum bacteria, the only gut bacteria who are dedicated to protecting their host, are vegetarians who thrive when their host eats fruit and veggies. Conversely, the "bad" C. perfingens bacteria thrive when the host eats too much meat, though they're more generally antagonistic than genuinely evil. While these portrayals oversimplify things a bit from real-world fact, these designations were likely created in order to reinforce one of the key lessons of the series, which is that diets high in fiber, fruits, and vegetables help promote good digestive health.
