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 three spin-offs; Bacteria at Work, Cells that Don't Work, and Cells at Work! BLACK. 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.