I believe they are from this manga 'Yuuhi ni Fureru Sono Mae ni' .
They must be in the same 'universe' so to speak, thats why the Mangaka said that it was an exchange program. She basically did a crossover of her own manga.
Ohh thanks! I already read that one but I seriously didn't remember them
...(￣∇￣")
I understand that, it was just a little like omake of them and sometimes after reading so many mangas remembering every single couple from every manga is impossible. I know I sometimes go through my read list and go "wait, I don't remember this one, did I read this?" and have to start reading it before I remember.
Oh cool Now I know what's my next goal I was looking for a good manga to read the ヾ(☆▽☆)
Fuck this idiot keyboard I was mean thx
Who was the other pair? Don't remember them...(⊙…⊙ )