[54] MVM Entertainment acquired the series for distribution in the United Kingdom and Ireland.
Ken - Kō - Dai - Ichi) by Red Blood Cell (Kana Hanazawa / Cherami Leigh), White Blood Cell (Tomoaki Maeno / Billy Kametz), Killer T Cell (Daisuke Ono / Robbie Daymond), and Macrophage (Kikuko Inoue / Laura Post),[8][56] while the ending theme is "CheerS" by ClariS.
She reminisces on being a young Erythroblast being trained by a Macrophage on how to be a Red Blood Cell.
She got captured by a Pseudomonas bacterium who intended to torture and kill her before moving on to other blood cells.
Part 1: AE3803 is assigned to be a mentor to a new red blood cell named NT4201, but finds herself out of her depth.
AE3803 is embarrassed when she gets them lost several times and finds that NT4201 seems to already know about the body, and that she prefers to do her job as efficiently as possible and not associate with non red blood cells.
The body suffers a head injury which results in massive blood loss.
NT4201 starts to panic due to the change in her perfect schedule, but AE3803 manages to get her back on track.
As the body temperature begins to drop, U-1146 defeats germs that entered through the injury, then is horrified to realize the number of red blood cells have depleted.
"Acquired Immunity": Memory Cell receives visions of destruction and believes he has gained the power to see the future.
When B Cell strikes him in frustration, he realizes he was actually seeing his memories of the past when the body received a Mumps vaccine.
Despite seeing the damage, Mast Cell refuses to release histamines until Basophil tells her to do what she thinks is right.
AE3083 delivers oxygen to him while U-1146 detects the bacteria and confiscates them for future disposal just as he is called to the stomach.
When Normal Cell saves the bacteria from falling debris, one of them beats up the H. Pylori, allowing U-1146 to kill it.
U-1146 is injured and Cancer Cell traps him in a pod, saying he's fascinated with him for the contradiction of being a defender when his function is to kill.
Cancer Cell strengthens himself by absorbing the carcinogens in the toxic gas and plans to kill the body so that everyone will be equal in death.
A light novel adaptation of the manga titled as Shōsetsu Hataraku Saibō (小説 はたらく細胞) was published on July 12, 2018, by Kodansha.
[70][71][72] A stage play adaptation titled Tainai Katsugeki Hataraku Saibō (体内活劇「はたらく細胞」) was announced in the August issue of Kodansha's Monthly Shōnen Sirius magazine.
[77] A tower-defense game for iOS and Android mobile devices titled Always Cells at Work (いつでも はたらく細胞, Itsudemo Hataraku Saibō) was announced in November 2018.
It was directed by Hideki Takeuchi and the script written by Yuichi Tokunaga,[79] starring Mei Nagano and Takeru Satoh as AE3803 and U-1146, respectively.
[82] Ian Wolf of Anime UK News gave the British Blu-ray release of the anime a score of 9 out of 10, and described the show as the most bloody on television, because so many of the characters are blood cells and thus means it contains more blood than shows depicting much violence.
[88] Dr. Satoru Otsuka, postdoctoral fellow in the molecular neuro-oncology department of Emory University School of Medicine in Atlanta, Georgia, praised the series' depiction of cancer cells during the series' seventh episode.
[89] Biology teachers at a high school affiliated with China's Southwest University were so impressed with the accuracy of the series that they assigned it as homework for their students.