This is probably one of the more unique animes I've seen, but not because it has anything super shocking or crazy out of the box about it. It's just because the entire feeling of the show is unlike any other I've actually seen solely because of how contradictory it is of itself, which I'll explain further.
The art is fantastic, I was shocked by just how beautiful it was from the start of each episode to the end. There's a high level of care put into the artistic details of My Happy Marriage and they clearly aren't willing to make any sacrifices in terms of quality. The character designs on surface level are very nice.
The plot and the actual personalities of the characters is where this falls very flat. Our main character, Miyo, is a victim of childhood abuse from her father, step-mother, and sister. I've seen a few reviews saying Miyo has no personality other than her trauma; I actually disagree. I can see how that could be perceived, but even if that was currently the case this early into her transition into a new life, it wouldn't be a negative thing necessarily. It can take a long time to open yourself up to being who you actually are when you never felt safe to do so previously. Regardless, I still disagree, because I feel like Miyo does have her own wants, dreams, and personality. If anything, it is our male lead, Kiyoka Kudou, who I feel has no real discernable personality of his own.
The show is incredibly slow in terms of pacing, but very quickly into the show we go from Kiyoka shunning Miyo completely to seemingly being in love with her. This is what I mean by how contradictory the show is. A slow-burn romance and plot, while not for everyone, can be executed VERY well. It can give ample time for characters to grow into who they are in front of the viewers instead of being laid before them as they are and never changing. It can give time for characters to fall in love realistically because they have genuine chemistry. This is not the case for My Happy Marriage. At least not in my opinion. Miyo and Kiyoka have no chemistry whatsoever. The only reason he has to love her up to this point is the possibility that maybe he just pities her. There are some sweet scenes, but they don't feel earned in the slightest because it feels so unrealistic.
On top of that, Miyo being completely subservient to Kiyoka just gives me the ick. Going from being a servant in a family that hates you to being a servant for a man that loves you isn't as big of a glow up as this show intends you to believe.
Other characters in the show are...fine? I guess? Miyo's family are evil without any real reason to be evil in the first place. Yurie, an old woman who serves Kiyoka Kudou, is sweet and I genuinely enjoy her interactions with Miyo. Kouji loves Miyo, seemingly, but we have no reason to understand why he does or what they went through together to cause these feelings.
It might seem like I absolutely despise this show but that actually isn't the case. The voice acting is great, the art is some of the best I've seen, and there are some really nice moments in this show that shouldn't be ignored. That being said, the show is somewhat boring because it's slow without any reason to be slow in the first place.
I recommend watching it on your own if you're interested in this genre and forming your own opinion. The show isn't horrible by any means, it's just very slow, and if that works for you then all power to you!