Preface

This review contains minor spoilers for Kitanai Kimi ga Ichiban Kawaii (KitaKawa). If you're just looking for a recommendation, I would say it's a must read for yuri fans that can handle it. The guro is only there for one chapter but it is a bit hard to read (I just skimmed it personally). Of course, it also contains sexual assault so be warned. However, after all that, this is honestly a really great story.
Also, go read 'Asago to Kase-san' or 'Adachi to Shimamura' after this because you'll need it.

KitaKawa

Kitanai Kimi ga Ichiban Kawaii (KitaKawa) is the most fetishistic depressing yuri tragedy I have ever read. It is a must read for all yuri fans that can handle it. This manga will make you feel many emotions. Be sure to take a shower after reading this.

I am not a fan of tragedies. In my view, a lot of them end up leaving the story unfulfilled. The only great tragedies I've seen are 'Romeo and Juliet' and 'La La Land'. I won't say KitaKawa deserves to be there but perhaps one tier below.

It definitely fulfills its role as a tragedy very well. The ending is depressing but it's the logical end for the characters. I would have loved for Ai and Hina to get a happy ending and just save their fetishes for the bedroom but that's not this story.

Tragic Yuri (Story)

KitaKawa starts off as a story about Airi Sezaki exploring her fetishes by sexually abusing Hinako Hanamura, a girl she cultivated a friendship with for this reason. Over the course of the story their relationship develops (or perhaps regresses?) ultimately leading to them living a life where they cannot live without the other.

In the first few chapters, Airi experiments with some simple abuse; it starts off with her receiving pleasure from Hinako vomitting. Very weird and unhealthy but this isn't the worst thing. She then blindfolds Hinako and leaves her alone for a very long time. That doesn't sound too terrible, does it? However, her ideas become increasingly more and more fetishistic until she forces Hinako to pretend to be a baby and forces her to eat bugs.
This arc ultimately ending with other characters finding out about this, and socially ostracizing Airi. Airi then shuts herself in her room and becomes attached to Hinako in the same way Hinako was attached to her, due to Hinako's abuse.
Eventually, they run away together. They try to survive but Airi decides that this life is not worth living and she should kill herself. She attempts to kill herself with Hinako but she can't do it. Later, Airi asks Hinako to strangle her, which she unexpectedly does. Her feelings towards Airi are a weird mixture between love and hatred that she can't bring herself to stop. She nearly kills her but stops leaving Airi with a breath of life left. Hinako attempts to carry Airi somewhere else, so they can run away again but they ultimately succumb to the cold and die.
Over the course of the story, there are options for each character to get out of the situation they're in but they both choose to ignore it and continue down this path.

After reading this story, I wasn't sure how to feel. I started typing up this review, hoping to capture the essence of how I felt; perhaps you started this review, hoping someone else did but I think that's part of the point. This manga covers uncomfortable topics that you don't really see in the fluff filled modern yuri landscape. It handles them all quite well, never glorifying it but ensuring to show the horror of it all, of how the abused can become abusers.
It does a great job at making the reader empathize with these characters, even at their lowest points. Even though I knew that these people weren't good, I just wanted them to sort their issues out but they didn't and ultimately met their demise for it.
There's a part in the story where you go from being completely disgusted with these characters to feeling pity and sorrow for them. And, at the end, you want them to be happy but they can't be happy and that's ultimately because they love each other. If they didn't have each other, they would have probably not met their end, but because they did, they died. I find that to be a very interesting take on obsessive love.

Beautiful Abuse (Art)

All that being said this is the best art direction I have ever seen in a yuri series, by far. The character designs are all perfect. The guro is drawn horrifically well. The cover art is ridiculously beautiful; it perfectly fits the story, with the watercolor blotches, the mosaic censorship, the fetishistic smile on Airi's face, and Hina's half-hearted attempt to hold her hand off.
Airi's design is a perfect allusion to other contemporary yuri with a 'long black haired, cool, assertive' character that has issues. Hina's design is almost angelic; she seems so innocent, especially with the clothes the author draws on her, perfectly fitting the tone of the story.
The important side characters also have great designs. Ichika, in particular, fits the whole idea of an attention with its obsession on cuteness.

The abuse chapters are very well drawn and succeeded in making me extremely uncomfortable. They show the dread that Hinako feels during the abuse and the ultimate joy that she gets when she's comforted by Airi, with the lighting and colors. The chapters depicting sex are also quite well drawn; those depict Hinako's abuse and obsession over Airi well. I like how quickly it shows Hinako becoming the abuser and in control, as if she always wanted to do this or had the power to do this, making the final strangling scene make more sense.

Overall

KitaKawa is a divisive work; if you look at the scores, there's an even amount in almost all of the ratings.
Of course, this is due to the uncomfortable topics it tackles. However, I fundamentally believe this work is a hidden gem under all of that if you can handle it.