Cells at Work! (はたらく細胞 Hataraku Saibō?) is a manga series by Akane Shimizu. The series is first conceptualized as a short story titled The Story of Cells. Later, Akane Shimizu authored and released a manga titled Cells at Work! which was first serialized in the March 2015 issue of Monthly Shōnen Sirius of Kodansha. It soon spawned seven spin-offs. An anime adaptation titled Cells at Work! was made by David production and aired from July 8, 2018 until September 30, 2018 with 13 episodes. Season 2 of the anime has been announced to air in 2021.