There is only one pairing publicly acknowledged by Namori, Nana x Rise. All the other ones are lost in the love dodecahedron that is Yuru Yuri.
That said, there are patterns that one can disseminate from all this mess. Take a little look, and you will notice that all the “true pairing” are the ones that do not acknowledge or are not aware of their feelings for each other. We have the boke-tsukomi childhood-friends pair of Yui and Kyouko, the only-pair-that-have-willfully-kissed-so-far of Akari and Chinatsu, the married couple yet still oblivious Sakurako x Himawari.
And thus, naturally, the only pairing left must be the remaining main characters, Chitose and Ayano. They are childhood friends, and being a romcom, this means that they must have some feelings for each other that they don’t realize. They always seem to be attached at the hip. They also have the support of their families.