The official Twitter account of the Aggressive Retsuko (Aggretsuko) net anime series announced a fourth anime season on Thursday.

The first anime adaptation based on Sanrio's titular red panda mascot aired in 100 one-minute episodes from April 2016 to March 2018 on TBS' Ousama no Brunch program. TBS subsequently combined all 100 episodes and broadcast them in 10 episodes. Pony Canyon released the anime in two DVD volumes in January and April 2017.

The first, second, and third season streamed exclusively on Netflix worldwide in April 2018, June 2019, and August 27 this year, respectively. A Christmas special titled Aggressive Retsuko: We Wish You a Metal Christmas debuted in December 2018. Rareko directed the short television anime and all three seasons at Fanworks.

Synopsis
Some offices have stereotypical dynamics: the chauvinistic pig of a boss who never does any real work; the employees whose goal is to suck up to the boss; the ones whose lives seem perfect; and the individuals who have all the actual work pushed onto them. Retsuko the red panda is in the last group, as she stays late most nights to make up the work her coworkers are too lazy to do themselves.

Her relief from the stress of her everyday life comes in the form of singing death metal at a local karaoke club. Night after night, Retsuko channels her grief into a microphone and considers the place to be her own personal sanctuary. But as she moves further away from her comfort zone and the ideas people have of her, she discovers that letting others into her world of death metal may not be such a bad thing. [Written by MAL Rewrite]

Source: Official Twitter

Aggressive Retsuko (ONA) 4th Season on MAL