- Base-Breaking Character: Naoya has polarizing opinions from audiences, with some viewing him as an absolute stud and an icon of manliness due to his earnestness, directness and uncompromising morality in stating exactly what he wants and doing whatever it takes to get it without dishonesty or deceit, or simply seeing him as entertaining and hilarious because of the silly things he does and the reasons he does them. Others see him as a manipulative, childish and selfish scumbag who is basically forcing Saki into a polyamorous relationship that she does not want and has no power over. Naoya also will not take no for an answer, becoming extremely persistent at getting what he wants the more someone denies him. While he has never been shown to be deceitful or verbally abusive, he does repeatedly ignore his girlfriend(s) outright begging him not to do something they don't want. He will also resort to extreme bargaining and self-destructive behavior that makes people who care about him have to concede or watch him literally kill himself trying to convince them. In any comment section, you will find a mix of people who are either calling Naoya an "absolute chad" or "toxic scumbag", whether or not they like the show on other merits.
- Broken Base: How the audience is supposed to see the love situation. Some are fine with it exploring how much of a headache a romcom harem would actually be, but think that Hiroyuki's madcap comedy is not the right approach for it and has to trivialize everything to make it work like it does now. The other half of the fandom enjoy it for the farce it is, and think the people who expected a more nuanced take on harem or the characters are taking the series way too seriously.
- Catharsis Factor: For Naoya's detractors, seeing him get humiliated or injured, mostly by Saki, can be satisfying to watch.
- Idiot Plot: Done completely intentionally for the work's role as a Deconstructive Parody. Our protagonist, Naoya Mukai, is already in a happy relationship with his Childhood Friend, Saki Saki, and he couldn't want for more. One day however, he's confessed to by Nagisa Minase, a cute and attractive Nice Girl with great cooking skills, and instead of turning her down gently and continuing on with his life, he rationalizes that since he finds both Saki and Nagisa attractive, he's obligated to two-time the both of them and keep them both happy, with Saki's permission of course. Instead of losing interest and dumping him over this, both girls actually decide to go along with it, Nagisa because she figures she won't get another chance with him otherwise, and Saki due to peer pressure from the other two and because she may or may not be attracted to Nagisa as well. And then you got two other girls, both knowing about the two-timing, falling for him as well, and one of them is the Only Sane Woman.
- Unintentionally Unsympathetic:
- Naoya constantly claims to be pursuing the two-timing relationship with the intent of making both Saki and Minase happy, and while he is unintentionally making them both Insecure Love Interests, we're supposed to believe that he has the best of intentions and is sincere in his desire to make both girls happy. That being said, it's hard not to see Naoya as displaying blatant favoritism towards Minase; he starts the whole relationship to accommodate her while effectively forcing Saki to go along with it, is hinted multiple to find her more physically attractive, not helping Saki's insecurities any, compromises his insane honesty-based morals to protect Minase from Saki's potential wrath when he discovers her searching through Saki's phone, and not once does it occur to him during Saki's constant attempts to prove useful in the relationship and eventually trying to have sex with him that she's in any way hurt by his actions.
- Some also see Minase in this light. While she doesn't come out of entering the relationship unscathed, with her own issues and insecurities, it can be hard hard not to see her as either someone suffering the consequence of her decision to go along with a two-timing relationship, or a blatant homewrecker who, like Naoya, is forcing Saki into the relationship so she can be happy.
- Shino is a friend that is genuinely concerned with how Saki feels in her two-timing relationship, but the fact remains that she's secretly gone after Naoya herself and constantly lies about it to Saki's face.
- Heck, even Saki doesn't escape from this. While there are quite a few fans that sympathize with her for her anger over the whole thing, there's also a number of fans who believe that her hair-trigger violent reactions to everything and her using her sexual curiosity to justify not dropping out of the relationship altogether add to the problem. It's also made clear multiple times by Naoya that he would stop if Saki committed to a firm "no", but at the same time it makes both of them unsympathetic because he's putting responsibility for his actions in her hands, and she could end this nonsense any time she wants but won't.
- The Woobie: Saki arguably has it the worst out of all the girls. At the start of the series, she's in a happy (if eccentric) relationship with her Childhood Friend Naoya and, in spite of his oddities, is very much in love with him. Then one day, completely out of the blue, Naoya approaches her with a girl named Minase, who's nice, sweet, has a more curvaceous body, and is a Supreme Chef, and says he wants to date the both of them. After getting understandably upset by this, she's effectively given a Morton's Fork to either go along with the two-timing relationship or dump Naoya and let him be with Nagise, and is effectively peer pressured into going with the former (which her friend Shino states is something that's easy to do with enough persistence). And then when the relationship starts and the three of them move in together, she becomes a major Insecure Love Interest over a sense of inadequacy towards Minase and the fact that she doesn't do anything to help around the house, not helped by all her attempts at doing so ending in Epic Failure, to the point that she resorts to Be a Whore to Get Your Man only for Naoya, out of a sense of fairness towards Minase, to turn down her advances, causing her to briefly drop out of the relationship and go back to her house. That's to say nothing of when Shino starts regularly interacting with Naoya, as she's hurt when she thinks her best friend might desire to get with Naoya too but places so much trust in her that she sincerely hopes it'll never happen.
YMMV / Girlfriend, Girlfriend