Forgot name of this manga

[darkaura]

It's a romcom. MC is a student. He had a childhood crush when he was younger. However it turns out that his childhood crush is one of two twins. The twins look identical, but one is male and the other one is female, and it's possible both are crossdressing. MC is trying to find out which twin is his childhood crush.

 

[undeed]

I've read at least 3 series with that premise
but
Futago no Danjo

 

[Manko-sensei]

Oh, a Hachimitsu Scans, then it's worth the try!