Popular with Furries: Retsuko has gained a lot of attention from furries since 2016 because red pandas are popular in the community. The anime series on Netflix only raised awareness and multiplied its popularity.
Relationships aren't and shouldn't be seen as a Happily Ever After case, nor a solution to your current life problems. They have their own plethora of problems and difficulties that show up through it, especially if you're trying to be with someone to gain something from them.
Overworking and over-stressing your employees doesn't benefit the company. Employees are people, too, and the employers shouldn't exploit or abuse them just because they can.
The Woobie: Retsuko leads a pretty hard life, being constantly abused by her bosses who make her do their work, is unable to find a good romance, has a pretty lonely home life and ends up taking her frustrations out by singing Death Metal with Berserker Tears. Fenneko raises the possibility she'll be Driven to Suicide in the future.
Resasuke's social awkwardness, the fact that he had to be coached and nudged every step of the way while dating Retsuko, and the scene of him returning home to his plants after she breaks it off begs the question of whether he was as miserable with her as she was with him.
Retsuko is oblivious to Haida's interest in her for the most part, and she falls hard for Resasuke. However, Haida's the first person Retsuko goes to in her plan to marry to get out of work, making some wonder if Retsuko had feelings for Haida before but it just didn't work out for that particular plan.
Animation Age Ghetto: Oh boy. Despite being aimed to the teen & adult demographic, and due to being in the same studio as Hello Kitty, Malaysia features the character as part of the promo poster for the Sanrio Times Exhibition held in December 2018.
Author's Saving Throw: While Puca carefree attitude came across as her being a Lazy Bum and careless, the Christmas Special shows she actually is working at her import business and is apparently so busy that she has to turn down Retsuko's invite to hangout.
Ensemble Dark Horse: Ookami, the main character's maned wolf coworker, got his own set of fans due to his cool looks and attitude, despite only briefly interacting with the characters during one episode and only appearing in the background afterwards.
The One-Scene Wonder with Haida dressed like a punk and owning a bass guitar has led to many people thinking that he is just like Retsuko in regards to lashing out after a cruel day of work. As a result, fanart tends to pair them both as a band of Death Metal.
Similarly, one of Resasuke's scenes reveals he's actually a Caring Gardener, to the point where he says hello to his many plants when he comes home. Many believe this is a sign that he's actually happier being with plants than he is with people, and that he'll be okay after such a messy breakup with Retsuko. Fan artists love to draw him with the various plants seen in that scene, even more so than his canned coffee.
Foe Yay: Tsunoda and Fenneko, almost every time they interact, reassure their soul-consuming hatred for each other, with both displaying strangely obsessive behavior, including Fenneko stalking Tsunoda's social media (down to figuring out a pattern for her posts) and Tsunoda inviting a blushing Fenneko to her single's meeting. It's also implied that Tsunoda is aware that Fenneko stalks her social media.
Gori cares a lot about Retsuko liking her, acts flustered when she tries to talk to her, cries when she thinks Retsuko is mad at her and spends the night at her house after drinking too much, and asks whether any guys are interested in her.
One of the few things that causes Fenneko to flip out is the idea of Retsuko becoming as social-media obsessed as her Sitcom Arch-Nemesis Tsunoda, going so far as to say Retsuko was one of the few "sane ones" in "Metal Christmas".
"this is a[n] [X] stan account now"Explanation From the Netflix Twitter account changing its bio to "this is an Aggretsuko stan account now". "Stan" is a term coming from a song by Eminem used to refer to people that follow something down to an obsessive degree. People change "Aggretsuko" for a work or a person (real or fictional) of their preference.
Furry awakening. Explanation Ben Diskin's twitter has an interesting journey, from discovering the fandom to discovering what vore is.
"Haida is a good boy" Explanation Haida's hidden crush on Retsuko, his being respectful when she's dating Resasuke, and generally being one of the show's more moral characters has caused the phrase to show up in pictures, videos, and descriptions of him.
Retsuko is a cute red panda that is dealing with a Soul-Crushing Desk Job due to her boss's harassment and abusive behavior, and it can't be helped to want to protect her, which is actually Haida's reaction.
Haida is a surprisingly cute guy due to his constant Luminescent Blushing around Retsuko and cute behavior towards her.
Retsuko can be heard vomiting in her death metal voice, which can be a bit jarring for people unfamiliar with death metal.
When Fenneko shows images from social media to Haida. He eventually gets creeped out and paranoid by her behavior and how often she uses it to check on everything. Fenneko then tells him if he thought that was bad, then he should stay off of social media since he isn't as familiar with it. It doesn't help that the way she said that made it sound threatening.
Paranoia Fuel: In-Universe where Haida gets freaked out by Fenneko and her constant use of her interpretations and stories behind pictures she's seen. Fenneko even tells him to stay off of social media if that was bad.
Periphery Demographic: The series has gained a following in the Death Metal and Heavy Metal communities in many countries where the genre is popular.
The Scrappy: Puko is a difficult character to like, as her easygoing lifestyle is predicated entirely on spending money that other people like Retsuko and her parents actually earn.
Spiritual Antithesis: Retsuko and the whole show itself can be one from Detroit Metal City, another show dealing with a main character (Soichi Negishi/Johannes Krauser II) singing Metal music as a part of their double life. While both Retsuko and Negishi sings Metal as a way to deal with their personal frustrations in their lives, this is when the similarities end: While Negishi (as Krauser) sings Metal partly because that's his job (even if he is forced to sing Metal against his will), Retsuko is just a fan of the genre herself, with no plans to become a pro soon. Also, while both shows deal with the Metal genre, Agressive Retsuko only use the genre as a Framing Device for Retsuko's personality, while DMC deals exclusively with the genre itself.
Stoic Woobie: Some people do feel sorry for Resasuke as his relationship with Retsuko breaks down.
Superlative Dubbing: The various localizations of the series are incredibly well done, liberally rewriting jokes where appropriate to make jokes funnier for native speakers and in some cases even improving on the original. Numerous videos on YouTube can be seen comparing the different translations to showcase the quality.
Unintentionally Unsympathetic: While Puko does try to help her high-school friend through a tough time, her carefree, easy-going lifestyle depends entirely on her having rich parents to mooch off of and responsible people like Retsuko doing all of the work for her. Her best advice to Retsuko's financial struggles amounts to "move back in with your parents." To the show's target demographic of millennials, the first generation in recent history to earn less than their parents and as a result generally struggle with the most basic living necessities, Puko ends up coming off as a Spoiled Brat.
Values Dissonance: The series shows that sexual discrimination in the workplace is much different in Korea and Japan than in many western countries, as pointed out in this article.
Several fans thought that Haida was an African Wild Dog before Word of God confirmed him to be a hyena.
Similarly, Ookami was confused to be a fox before it was confirmed he was a maned wolf.
What Do You Mean, It's Not for Kids?: Sure, it's made by Sanrio, the creators responsible for Hello Kitty and othersimilar characters, and it retains the cutesy animation style. However, Aggretsuko is the second Sanrio creation that is geared towards the teen and adult demographic (the first being the Show by Rock!! franchise), and it's more explicitly shown in the Netflix series than in original TBS shorts. Retsuko drops some strong language while in Rage Mode, and she, along with the other co-workers, is seen drinking alcohol to the point that she passes out. On a less extreme note, it's much more grounded in reality than other Sanrio series, with the characters dealing with job pressures, debilitating stress, and even sexism and other forms of harassment with Reality Ensues-forms of consequences.
The Woobie: Haida is a sweet guy who can't manage to land the girl he likes, despite her being right around him all the time. He seems to have his self-confidence particularly mined after Retsuko ignores him in favor of Resasuke.
The English dub contains a few, including Fenneko referring to Resasuke as a "space cadet" instead of an "out of pocket prince." Ironically, this makes the episode's title (Out-of-Pocket Prince) sound nonsensical unless you're familiar with the translation's changes (or have JP subs on).
Another similar case with when Ton starts calling Retsuko "Calendar" in the English dub. The English subs use the nickname "Short-Timer" instead, which is the name of the episode where the nickname is first used.