There is nothing wrong with growing at different rates, but schoolyard friendships sometimes go this way.
Man... was I precocious and childish at the same time.
I read the entire thing. The cheating did not make things better, they should have just been honest with their partners and break it off sooner but they were too afraid of communicating. If you can't tell your partner when you felt a bit of a crush for someone else, that enough should be a flag...
you know how in romcom manga people are like "he didn't do much except being the base level of polite and all the girls are falling for mc" or things like that... if the other options are like the husbands of these two, I can see why politeness is a romance aspiration for japanese women geez...
I think Yuu not facing his inferiority complex is what he did wrong, like she's his best friend and he doesn't ever mention "oh, I have/had a girlfriend" ? I think he was ashamed of what he was doing with Yami.
Hikari took Yuu for granted, by thinking he would be there for her forever is what...
ngl I want to see her facade fall and what his reaction would be to it. I can see a world where her being genuine gets a warmer reception by the protagonist even if she is still mean
I think the reason it feels unsatisfying is that breaking the loop was such a BIG point of this story and yet it just... happened for no clear cause.
There was no fanfare, no action from our protagonists or even anything to do with them that broke the loop.