That's not how human relationships work.
Sure, she pushed him into coming - which is normal between friends, or when you want to drag your crush somewhere. You don't just ask once and give up, because sometimes people are just obstinant. At my age, I won't go anywhere, but when young, you are prone to be influenced by your friends "come on, it will be fun" said over and over. And that's just how it is. This is not a major demerit.
She left him unaccompanied - totally normal when you invite someone to some kind of school activity. If you ask them to come to your sports game, they accept that they will have to wait until the game proceedings are over. If it's a festival, they will have to wait for you to have time off - because in those cases your obligation is first to other people involved in the event. This is the teen equivalent of work - you can't just ditch because your friend came to visit.
hassled by her friends - obviously normal when your friend's crush comes to visit. Even if it's just a good friend of a friend, the school friend group will want to check him out if there is a chance.
Those are all things Yuu accepted when he agreed to come - reluctantly or not. Hikari did nothing wrong.
Yuu, in turn, ditched her for hours with no contact, the second they were going to meet up. We don't know his thoughts on the matter yet - if he thought that this was just a casual hangout, then he was just being a regular size ass for that. But if he had an inkling of Hikari being into him, and/or was still trying to get together, and he still ditched her in this way, he is a massive PoS.
Usually, I'm on the side "Yuu didn't try hard enough to get with Hikari over the years, but he doesn't owe her anything, so what he did is his business". So if he exchanged contacts after the kiss to talk about the situation, and left because he had another, prior obligation - this would be completely fine on his end even if he ended up with Yami.
But him ditching Hikari in this setting put him clearly on a-hole list. He is not as bad as Yami - as long as he wasn't aware of Hikari courting him or still trying to court her - but he is definitely the only one who fucked up between him, and her.
What Yuu did in not answering her texts starts at rude and gets worse from there depending on what actually happened offscreen, given that he's the one who asked her text. And all the lies after make it really seem like he sucks.
But Hikari, inadvertantly and through negligence, created the
perfect opportunity to be ditched. Arguably, an occasion where what Yuu did in leaving a note and bouncing was almost required by etiquette.
See chapter 19 for her invitation, which was cute and relatable when you have access to her inner monologue, but absolutely
not cute from Yuu's perspective, and was not "come on it will be fun."
When you invite someone to an event in a capacity that's more than "hey anybody want 10 free tix to [blank]," such that you have "plans" with them,
you are the host. You are assuming responsibility for them having a good time, and that comes with certain responsibilities that Hikari failed to live up to. "My shift ends at 1400 - let's go around after!" That simple text, sent at whatever time that morning she knew for sure what her schedule would be, and before Yuu left the house, would satisfy the requirements of hospitality, here. It never came. Not every student at the festival will be working a shift during the festival, but you really hope Hikari at least mentioned that she would be to Yuu.
When Yuu arrives at the maid cafe, her surprise greeting of him leaves her so embarrassed that she runs away to the prep area and hides from him to talk with her friends. Enough time passes with him sitting there that a Yuka is now sitting across from him Being Weird, and Hikari finds time to dart out from the prep area, snatch her friend away without a word to him, and flee back to the prep area. Hikari continues to melt down with no real progress toward speaking to her guest. Again, it's not like they're working hard back there - they're bullshitting/freaking out and ignoring him.
Eventually (<10 min, but enough time to finish his drink) he leaves. Being alone (1 ticket) and stared at and ignored was apparently more than he was willing to deal with. At least he left a note, in case she didn't have her phone on her.
It kind of seems like Hikari wants to have it both ways - a "school festival date" hidden behind the plausible deniability of "well I only invited you to come to festival, not hang out with me." I wouldn't blame Yuu if this made him feel unimportant in her eyes.
All of the above sucks and is really inconsiderate. Don't do that. I don't care if what Yuu did in not reading her texts is morally worse (it is,) because that shit hadn't happened yet. I won't quite stop being friends with you if you do that to me, but you absolutely get a mental note about all future plans. It's not "did nothing wrong," it's a series of fuckups.
Edit: She has the decency to feel bad about it and probably wouldn't do it again, which is part of why she deserves better than all this, but she did goof.
