'Aggretsuko' season 4 ending explained: What was Haida's secret?

The beloved Japanese animated comedy series Aggretsuko is back with another season. Season 4 of the series features Retsuko's return to the workplace and a new regime that causes new troubles for her to deal with. But she is not alone: Haida, her friend-zoned co-worker, has his own problems going on.

Season 4 of Aggretsuko released on Netflix on December 16, 2021. While there won't be as much death metal singing and features from OTM Girls, Retsuko has a new mission this season. Created by Rarecho and voiced by Kaolip and Komegumi Koiwasaki, Maki Tsuruta and others, season 4 of the series is just as binge-worthy as the previous seasons.

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'Aggretsuko' season 4 synopsis [Spoilers ahead]

The end of season 3 of Aggretsuko saw Retsuko shutting herself away from the rest of the world after a humiliating encounter with a toxic fan.

In season 4, she returns to the workplace along with Haida, who has resolved to keep her safe. The two of them do the will he/ won't he dance as Haida remains incapable of asking Retsuko out. He is paralyzed by his fear of being a nobody while Retsuko is special and thus, out of his league.

Season 4 of Aggretsuko also sees a new boss at the trading center. Himuro, the external director, ascends as the new CEO and stirs trouble. He lays off several workers and also fires Ton. All the while, he has Haida in his confidence promoting him as the new director of accounting. Being valued and appreciated for once, Haida does everything Himuro asks of him.

However, Retsuko eventually finds out that Haida had been window dressing the accounts on Himuro's orders and hatches a plan along with her friends to stop him.

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'Aggretsuko' season 4 ending explained: Haida and Himuro exposed

In the final episode of Aggretsuko's fourth season, Retsuko, with the help of Ton, Manaka, Fenneko, Kabae, and Hyodo, manages to uncover the original and the inflated accounts on Haida's computer. In order to access the flash drive containing the accounts, Manaka and others pretend to be officials performing a surprise audit. As Haida rushes to meet them, Retsuko enters his office from the vent above and copies the accounts.

A jealous Haida also confronts Tadano and tells him to back off only to learn that there was nothing going on between Tadano and Retsuko. Ton brings Haida to Retsuko, who knocks some sense into him and tells him to stop following Himuro's malicious orders.

Haida breaks down and confesses that he never felt valued by anybody and when Himuro appreciated him, he did his bidding, all for Retsuko so that he could become deserving of her. Retsuko still tells him to do the right thing.

When Haida confronts Himuro about the employees threatening to expose his window dressing, he decides to fight them to the bitter end. However, Haida tells him that he's out and won't be a part of his scheme anymore. The two engage in an arm wrestling contest while Retsuko comes in with a death growl, throwing both Haida and Himuro out through the window. They are saved by Hyodo.

At the end of Aggretsuko season 4, Himuro steps down as the CEO and the former CEO returns to take charge. Ton and Kabae were reinstated and Haida quit his job. Retsuko and Haida remain friends and Tadano becomes president of a space venture.

Aggretsuko season 4 is now available to stream on Netflix, along with the show's previous seasons.