Lets talk about Yayoi, and what we understand of Akihiko and his changing feelings towards Ugetsu and Haruki through her eyes and behavior.

And the curious case of one Kaji Akihiko.

I feel like Yayoi has known Aki longer than Haru.
They're in the same year, so it seems feasible
Nd one of Yayoi's first impressions of Aki is he wouldnt hide whom he loved at all. His eyes always followed them.
(Yh its not like he changed. its just that NOW HE CAN BE HIMSELF)

So she knew of Ugetsu and should've known that she had no chance?
But still she jokingly confessed to Aki, and he politely turned her down.
Yet she didn't give up entirely. I'm guessing Aki's behavior changed somehow, and she thought she could have a chance, even if a little bit?

So, even after she was rejected we seen her riding together with Akihiko.
Aki seems pretty fond of her. He has a tendency to take care of people he likes anyway. And he likes Yayoi, that much is evident.

So much so, that Haruki thinks that she is his girlfriend.

Akihiko's behavior is pretty curious here too. We know that he was trying to hide his shameful gigolo image from Haruki.
Like here, in this flashback, he noticed Haruki and he is all like, 'don't talk to me now.' to his companion.

But when it comes to Yayoi, he has no such compulsions. On the contrary he was the one to call Haru out in this panel. It's more like he wants Haru to notice him with this respectable beautiful girl, (who is also Ueno's sister)
Yayoi is not harmful for his image in front of Haru.

It's more or less clear that at this point of time Akihiko wasn't thinking of ever trying to woo Haruki, or date him. He was just hiding his true self and his ugly relationship and his shameful lifestyle from Haruki as not to make him hate him, or see him as inferior.

But it didn't change the fact that he was inadvertently falling in love with Haruki.
Here's one thing I am sure of, Aki met Haru right after Ugetsu broke up with him out of nowhere, and twas from the very 1st meet that Haru became his savior, his go to comfort blanket if you will

Well, so going back to Yayoi, she went to the summer competition, of course for Ritsuka, but more importantly to try to get closer to Akihiko.
She totally wasn't aware of Haruki at this time. But she was wary of Ugetsu, as she should've been.
Just look at her face.

Ah! These panels are hilarious, they were funny the first time I read them, but in retrospect, they are even funnier.
Haru jealous of the person he thinks is Akihiko's gf, Yayoi wary of the person she thinks Aki's in love with but may be slowly getting over.
And ugetsu all smug.

He has no idea what's gonna hit him ToT
Anyyyway, here's where things get interesting.
At this point Aki had trauma bonding with Ugetsu, but he had fallen in love with Haru.
From right after Ugetsu showed up, Aki's behavior is noteworthy. He is on edge and extra clingy to Haruki.

Look at his face! There was no reason for him to be that shaken.

Because of the more obvious tension between Mafuyama it was easy to miss, but Akihiko was very not himself here too.
And he was looking for Haruki to keep him grounded.

This panel here is from Aki's viewpoint.

And then in the very next panel we have this Yayoi, noticing the look on Akihiko's face looking at Haruki. We can't see his eyes, keeping true to Kizu's style.
But yeah it's the very next panels.

And then here Aki is following Haruki just because.

Really, he didn't need to follow Haruki like that that very moment.

Ritsuka had already took off, things had been taken care of.
He just needed to be closer to Haruki to calm his nerves, what with Ugetsu's presence putting more pressure on him.

And notice these panels of Yayoi, uncannily similarity with Ugetsu's saying bye bye Akihiko while he goes chasing after Haruki.

Look at them right after Akihiko was like 'I gotta go', he is just chilling with Haruki.
Not even saying anything, Haruki is the one totally in lead here. Looking after everyone, calming everyone down.

And the moment Haruki is trying to go do things a little away from Akihiko, Aki is all like, I will go with you too.
He is not needed there, Haru isn't even looking at him, Take Chan is one of the organizers and obviously Haruki is the one to set everything up for their band.

He just can't be away from Haruki for a moment.
And he needs Haruki to look at him, pay attention to him.
Yes, he wants Haruki to know how important he is, but that's more for his own sake than Haruki's sake here.

Haru might have not noticed, and we might have not noticed the first time reading it, but really, Haru just saved Aki here again too. Not the band, but Aki himself.
And how cute is his I might end up dying too? Knowing Haru will react this way? He just want Haru to care for him

And Yayoi witnessed it, and witnessed Aki looking at Haru during the performance. And how heartbroken she must had been, to know that Aki is surely getting over one person, but has fallen for another one like this, too deep, too desperate? And it's not her?

Her love remained one sided.

Thank God for Take Chan!
He is way better for Yayoi than Akihiko could ever be anyway.