Why? I believe that Nagatoro-san is a very enjoyable story about two teenagers maturing and finding themselves and their place in the world.
First, let's address what I believe is the main turnoff of this manga - its ruthless depiction of bullying and teasing, especially in the first few chapters. Nagatoro is presented as merciless character who bullies her upperclassman (or you might say senpai) because he looks and acts like an introverted loser. Personally, I understand why some people get turned off by this - she's a dick for sure. What I feel like people miss is how she bullies her senpai. She's not thoughtless, and you could feel a sense of kindness even in her most degrading acts. She knows when to stop, and most importantly, she doesn't act that way towards everyone she meets. It's just him, Hachiouji, that she acts like this, simply because she sees something in him.
Getting over the rocky start, this story truly converges into a unique tale of maturing. Contrary to her exterior, Nagatoro is a normal high school girl with very normal high school girl troubles. She's scared of people surpassing her, and so she cuts off her only hobby - judo. She just wants to be in her own world, and not be hurt by the sight of people triumphing over her. This in turn makes her empty inside. However, Hachiouji only has his hobby as his validating point. He doesn't excel in sports or academics, but he enjoys, and is good at art, and he makes it his only support. He believes that art is all he needs to get the peace and tranquil he wants in his school days.
Looking at her senpai, who she mocks because he seems to only care about art, Nagatoro realizes how important judo is to her. She needs a validation point too. She doesn't want to be remembered as the ordinary high school girl who looks like a deliquent and has no hobbies. She doesn't want to spend her high school days in boredom. She wants to change.
Looking at his kouhai, who seems to be the worst person in the world, Hachiouji realizes how narrow he has been. How boring the peace and calm he has been seeking will make his school days. How beautiful and exciting the world around him is. How, even in his pathetic state, he wants to be somewhat outgoing as Nagatoro. He wants to change.
Both of them owe each other for that change. It's like finding your missing puzzle piece to complete yourself, to become an adult, to shed all of the childish thoughts and habits that is still hanging on to you. That is what makes this manga so charming and exciting to read. You want to find out how they grow and become closer to each other.
Aside from the duo, the other characters do a great role of supporting and encouraging them in their search for themselves. The characters have an amazing dynamic which feels very natural despite being awkward at times.
We could not talk about Nagatoro-san without mentioning Nanashi's amazing art. Sure, it could be repetitive at times, but the facial expressions and judo scenes (and the art in general) are really well-drawn and make great meme material.
Overall, this is a great manga about coming-of-age. Change is hard, teenagers can have a tough time learning how to deal with the people around them. This is a great and wholesome portrayal of how finding your missing piece can have a profound impact on how you see the world around you.
