From the description of Masamune-kun in the beginning I was very weary to try it out. Would it just be the ecchi equivalent of revenge porn with an unfortunate harem? Would his love interest be someone redeemable? Would I even enjoy it knowing it would succumb to the idea of a harem? As the show began to air it got generally good reviews and so I opted to take a look. Maybe it would offend me and maybe it would be something I hate but there was a sliver of a chance that maybe it would be an amazing show that brings a new air to the idea of animus.
Well, it wasn’t really that. I watched Masamune-kun’s first and second episode and found myself feeling a lot of what I do during anime. When I was younger I could simply watch the antics of high 
schoolers as they do cute amusing things in the glorious land of Nihon. As I grow older it begins to develop into a difficulty for me to engage in the same thing. Why, I ask myself, would teenagers run into a spider and low their entire cover for the sake of said spider? Why, I ask myself, do I watch the show when the primary goal of the two protagonists is to hurt each other worse? I got the feeling I knew where the show would go eventually: You see Masamune-kun is a story about a kid who was called a pig’s foot by the object of his affection because he was a fat child. In order to seek vengeance he has become thin through hard work and plans to make her fall in love with him and then reject her horribly. His ‘victim’, Aki, is dubbed the Cruel Princess because she rejects every boy in as mean a way as possible. As an anime fan the only way this seems like it will go is that the main character genuinely falls in love with her and this time she accepts his affections or something along those lines.
Because animus.
So here is the real premise: Two people who act really awful in some way or another, Masamune on the inside and Aki on the outside, are actually not super terrible in every way and will learn to get better through adventures of being teenagers. This is honestly one of the best ways Masamune-kun could have gone from the beginning, as anime has actually gone out of its way to be purposefully bad and make characters who are genuinely spiteful, but it still stands the same as being predictable. Masamune has a hard time maintaining his hateful attitude and instead seems more focused on self deprecative things. Think about it, how often does he genuinely think about revenge in ways that are explicit as opposed to genuinely changing things about his own life? How many times have we seen him reject food based on calories or micromanage the exercise he takes because he simply can’t gain weight? He’s clearly suffering as a person and this anime will likely confront those parts of himself even if the theme is never stated explicitly. And Aki has her own issues (though admittedly she is a bit more shallow as her worry is not seeming cute because she eats like a monster)- issues I’m sure we’ll learn more about eventually.
So the question becomes: why don’t I enjoy that struggle? As it stands a lot of anime focuses on the harem type show and succeeds because of it. I have sat through and enjoyed countless harem 
type shows where the main characters waifus are really the main point and everything else is pointless. I have seen shows like this where the main characters are the focus and the waifus are more or less for the viewers entertainment. Even now I’m charting up how I don’t dislike this girl or that girl because of X point and how I’d be excited to own a figure of x girl but not y girl. A lot of anime enjoyment in recent years has seemed to circle around the singular concept of the waifus and the way the waifus grow. Even as Masamune-kun promises to explore the nature of the main character and how he grows around the concept of waifus, I still find it is too focused on waifus. So I realized at this point that anime fans are essentially splitting into different sub groups that isolate me from this particular show.
Masamune-kun exemplifies the stereotype of an ‘otaku’s’ type of show. There are many fans who want to sit down and enjoy a comedy harem. It gives them joy not to see a humanist theme explored or a world ending crisis averted but to see a love theme explored and a misunderstanding averted. Many fans want to see their favorite girl as a figma and they’re interested in seeing them exist as school kids living their life. If you add in the romanticism of the Japanese lifestyle in western culture it becomes even more fun just to see people hang out in gym class or eat their cute school lunches. Some people enjoy that kind of show and to some people that is what being an ‘anime fan’ is about. My inability to enjoy the show because I am bored of the themes just indicates I am not an anime fan of that type. Can I objectively go “this show is fucking garbage!!!!” because I’m more of a fan of 1984 mind games and punching anime? Well no, then I’d just be a terrible reviewer. Personally, however, Masamune’s themes are very vague to me. I am sure it has a lot of things about it that make it enjoyable and fun- but nothing that I myself would find to be those things. Perhaps if the series really takes a turn for the more positive I will check back in to give a final series overview, so be on the look out if something world shatteringly good occurs.
Even though I’ve yet to meet all the waifus I will be checking out of Masamune-kun out of this quick look. Even if it has some cute elements, it’s just not my style. Or, as I should have just said from the beginning:
I’m gettin’ too old for this waifu shit.
Oki
There’s actually a huge plot twist in Chapter 39 that overturns what you’re predicting in your first paragraph about how the show goes, but I can’t tell you what that is without spoiling it.
For me, I like that struggle a lot. Because it shows how they’re just people like you and me struggling with their own problems. The opening song goes like, “You can’t just pretend to be strong by being pretty. See, even roses have their thorns, don’t you agree?” I can relate to them a lot. Both of them act tough when they’re both really struggling with problems on the inside.
I think it’s fine if you’re bored of the themes. I personally do the enjoy the comedic moments, but I think it’s really the struggle that makes me like this show. I mean, there is a strong focus on the harem and the waifus, and it’s understandable that that could be boring for some people.
Oh trust me, there are many valid reasons to like the show as well as dislike it! I don’t chagrin you at all for finding those things enjoyable and as they progress feel free to reply to me and we will have a dialogue!