I still can't tell if the intended read is "they've each continuously been failing to notice the other person getting flustered the entire manga" or "Yuzu successfully suppressed her feelings until after the culture festival and is only now getting flustered".
Also, Yuzu being this traumatised makes me think of Yokoe from School Zone. Except the inciting incidents are so different in severity and recency that Yuzu just looks like an idiot. Imagine looking like an idiot compared to Yokoe lol.