Cells at Work! (はたらく細胞) 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 white blood cell she frequently encounters. It was serialized in Kodansha's manga magazine Monthly Shōnen Sirius from January 2015 to January 2021. It is licensed in North America by Kodansha USA.
The series has been adapted into an anime television series by David Production, with two seasons broadcast from July 2018 to February 2021, totaling 21 episodes. A theatrical anime titled ''"Hataraku Saibō!!" Saikyō no Teki, Futatabi. Karada no Naka wa "Chō" Ōsawagi!'' premiered in September 2020. The series has also spawned several spin-off manga series, including Cells at Work! Code Black, published from 2018 to 2021 and adapted into an anime television series.
Plot
The story takes place inside the body of an adult human, 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.