And Eru goes straight to the top of my Secret Girl list. That was definitely overcompensation for something.
Hehe, solid guess over here! But rereading chapter 1 tells me that whoever the girl is, she's going to keep watch on Girly and his Kitano buddy for a while, since he screwed his reputation on the first day of school for the sake of the secret girl. She may lay low for quite some while before actually showing up, and if it comes down to it, I wouldn't be surprised if she crossdresses as a boy to hide from the spotlight. Not to mention she's literally the only girl in the whole school, and not just Girly's class.
And I probably would guess Eru's letting Girly and Kitano take the risk of finding out the girl for sure while he stay in the background. It has already been established that openly speculating any person's gender here would be quite rude, since finding the imposter would mean throwing her to the wolves. The only method I can see working is the process of elimination, because there's no way any student who's not in the know can pinpoint just one person. 9 out of 10, they'll fail again before (probably) forming a solid plan.
Forgot to say something from my last comment, it seems that Eru also came to this school hoping to get a girlfriend, and he also dislikes the idea of becoming friends with Girly and Kitano...but for some reason he also crossdresses. That's kind of curious. Does he believe that looking like a girl more will boost his chances of scoring a girl's love points, or is that just how he is?
I think we will have some It Doesn’t Make Sense cases in the classroom, like, I’m sure others co-ed school exist who are close, there is no reason on going to this one lol
Maybe two options, the author didn’t think thing through and just made the whole class crossdress because the only think he thought was the main idea of “Girly will have to find out” and didn’t notice the plot-holes
The other option, someone asked everyone to dress like this the day before class started, a “mastermind” type of situation
That makes sense, because Eru sounds definitely doesn't sound like those who actually take crossdressing that seriously. He just ... has those clothes on for some reason, and if he came here to get a girlfriend then I do not believe crossdressing against your own preferences is the way to go.
There exists people who try to do this for the sake of blending in with girls, and frankly that's just lying. I know it sounds cheesy but people who were honest with themselves and are consistent gain more trust.