I can see that a lot of people don't like the direction the story's going right now, but I think this is actually pretty good. Tsuzuri's a good foil to Nishino, and I do think that she plays an important role in the story.
At the beginning, Nishino is constantly pushing boundaries, and it can be easy to interpret that as her being rude and inconsiderate. To a certain extent, you might think "shouldn't she be more respectful of his feelings and germaphobia?" Like, she comes off as really insensitive sometimes!
But Tsuzuri's introduction shows why that's not the correct answer. Tsuzuri is respectful of his feelings and of his germaphobia; she makes sure not to touch him. But while she's able to become friends with him like that, we ultimately see that that's not what he needed. He needed someone that would push his boundaries like Nishino does.
Tsuzuri's character does a good job of showing that and making that clear. Even if losing heroines can be a bit disappointing or annoying, I think that it's important to remember that this is a story first and foremost, and Tsuzuri is a massive asset to the story's themes.
100% this, but it still utterly gutting to watch Tsuzuri being supportive and absolute sweetheart being slowly drug through the wringer like this - arguably BECAUSE she's such an absolute sweetheart. Like she doesn't deserve any of this.
They made plans to go to the festival together. It's kind of rude to ditch someone you went to an event with in order to spend time with someone else, unless that was the expectation going in. This is basic courtesy, not "monopolization" or "guilt tripping" or whatever else you are projecting onto the situation.
They made plans and she came all the way from the place she moved to and got dressed up too. But they weren't planning on hanging out the whole night - she was going to take the train back home.
I'm not blaming any of the characters; they are all very realistic with understandable motivations
Tsuzuri was too kind to push Nakayama, he was too used to keeping people away and as we saw from him distancing himself in middleschool, didn't want to be close and cause her difficulty so the possibility of them dating never seriously crossed his mind and he's reeling. She has a crush, she was willing to sacrifice having a "normal" relationship to be close to him, deal and navigate around all his shit... only to find she's been left behind.
Yes she's being selfish
Nakayama is not even remotely close to being emotionally equipped to deal with what just happened. His best friend - his only friend - the person he non-romantically cares about the most in the world (before Nishino came along) is now dropping a bombshell on him he never expected or saw coming. All while he's navigating dealing with a crush of his own. He just never even considered Tsuzuri in that light and now is left with a hard choice - and utter lacking the social skills to have any hope of navigating it without a lot of destruction.
The writing of the characters is good, they are understandable with consistent and understandable motiviations.
The angst isn't at the characters, or even the writing quality. It most that the mangaka created Tsuzuri pretty much just to suffer, is dragging out her suffering, and she's such a cinnamonbun its really hard to watch her get put through it.
