Cells at Work! is a Japanese manga series written and illustrated by Akane Shimizu. It features the anthropomorphized cells of a human body, with the two main protagonists being a red blood cell, and a neutrophil she frequently encounters. The manga was serialized in Kodansha’s shōnen manga magazine Monthly Shōnen Sirius starting in March 2015.
The manga was launched in Kodansha’s shōnen manga magazine Monthly Shōnen Sirius in March 2015. Kodansha has collected the manga into five tankōbon volumes as of October 2017. The manga received a spinoff in the May 2017 issue of Nakayoshi called Hataraku Saikin by Haruyuki Yoshida, which follows the lives of good and bad bacteria in the intestines. Another spinoff, titled Hatarakanai Saibō by Moe Sugimoto, about immature red blood cells (erythroblasts) that do not want to work, was launched in the September 2017 issue of Monthly Shōnen Sirius. Kodansha USA announced that it had licensed Cells at Work! in North America on March 21, 2016. The manga is also licensed in Taiwan by Tong Li Publishing. The manga received another spinoff titled Hataraku Saibō Black, set in a “black” environment of a human body suffering an unhealthy lifestyle, that runs in Weekly Morning since June 7, 2018. It is written by Shigemitsu Harada, with illustrations by Issei Hatsuyoshi and supervision by Shimizu.
The story takes place inside the human body, where trillions of anthropomorphic cells each do their job to keep the body healthy. The series largely focuses on two such cells; a rookie red blood cell, AE3803, who often gets lost during deliveries, and a relentless white blood cell, U-1146, who fights against any germs that invade the body.