During its Netflix Festival Japan 2021 event, Netflix released a new trailer for the upcoming fourth season for Aggretsuko and revealed its December 16 worldwide release date.
Rareko will return to direct the anime at Fanworks. The anime’s previous cast will also return for the fourth season.
The first-ever Aggressive Retsuko anime premiered in Japan in April 2016 and ended in March 2018. The first Netflix anime premiered worldwide in April 2018. The second season premiered in June 2019, and the third season premiered in August 2020.
Netflix describes the anime as:
Frustrated with her thankless office job, Retsuko the Red Panda copes with her daily struggles by belting out death metal karaoke after work. After becoming an underground idol to pay off her debts, Retsuko decides to quit OTMGirls and enjoy living a happy, normal life… but just as the company she works for is facing big changes, her relationship with Haida finally begins to move.
Source: Netflix Anime Twitter account