I think that since ch 00 it is clear that Ran has deep feelings for keiko.
She probably has no interest in men, while the first time you saw keiko said: WOW.
And Keiko is the only person that does not take away with her humor. At the university, with her former classmates, even with her mother, keeps everything at a distance, while with the stretch, (born of a jealousy ran for Keiko's ex-boyfriend) has a contact with her.
Also I hope they have the courage to recognize their own feelings, and that some conventions, some wounds that have both, do not make them express.
But if it does not happen, well, if told well, it would become less beautiful this manga, because these things happen in real life.