Aniplex revealed a promotional video during the " Aniplex 48-Hour TV" livestream event on the AbemaTV streaming service on Saturday for the second season based on Akane Shimizu 's Cells at Work! manga. The video reveals that the anime will premiere in January 2021.

Additionally, the livestream also revealed that a theatrical anime based on a story from volume 5 of the manga will premiere in theaters in Japan on September 5. The announcement stated the anime will screen in theaters before it airs on TV as part of the second season. The theatrical anime's full title is: Tokubetsu Jōei-ban "Hataraku Saibō!!" Saikyō no Teki, Futatabi. Karada no Naka wa "Chō" Ōsawagi! (Special Screening Edition: "Cells at Work!" The Return of the Strongest Enemy. A Huge Uproar Inside the Body's "Bowels!").

Hirofumi Ogura ( Black Butler II , Null & Peta ) is the new director of the second season (and the theatrical anime) at David Production . Yuuko Kakihara is returning to write and oversee the series scripts. Takahiko Yoshida is returning as the character designer, and Kenichiro Suehiro from MAYUKO is returning to compose the music. The anime will also feature a returning cast.

The first television anime adaptation of the manga premiered in July 2018 and aired for 13 episodes. Aniplex of America streamed the series on Crunchyroll , and Funimation added the show in February. The company released the anime on Blu-ray Disc with an English dub last August. A new anime special aired in December 2018, and Crunchyroll is streaming the special.

Aniplex of America describes the story:

This is a story about you. A tale about the inside of your body…

Enter the fascinating world inside your body where roughly 37.2 trillion cells work hard for you 24 hours a day and 365 days a year! The cell-sational action comedy Cells at Work! that has garnered praises from a wide array of audiences, from casual viewers to professionals in the medical field is the latest hit edutainment now on Blu-ray. The show is available with English audio, while also showcasing the English version of the opening theme song in each episode. Carry, fix, fight! Don't miss out on your chance to own the only series starring your Cells at Work!

Shimizu launched the original Cells at Work! manga in the March 2015 issue of Kodansha 's Monthly Shonen Sirius , and Kodansha shipped the fifth compiled volume in Japan in August 2017. Kodansha Comics is publishing the manga in English, and it shipped the manga's fifth volume in English in November 2017.

The manga has inspired several spinoff series such as Hataraku Saikin (Bacteria at Work), Hatarakanai Saibō (Cells That Don't Work), Cells at Work! Code Black ( Hataraku Saibō Black ), Hataraku Saibō Friend , Hataraku Kesshōban-chan (Platelets at Work), Hataraku Saibō Baby (Cells at Work! Baby), and Hataraku Saibō Lady (Cells at Work! Lady).

The franchise has also inspired two stage plays, which ran in November 2018 and September to October 2019.