Damn looks like I am the only UtaxKaoru shipper remaining here. Sad times.
Well, the Kaoru that started out the series was a plausible object of affection—she clearly felt deeply for Uta (as much or more deeply than for her husband), she was very skinship-y, and she kept doing these quasi-romantic things—remember the necklace gift atop the Ferris wheel?
It looked at that point like she just needed to become more aware of the nature of her feelings for Uta and, abetted by the fact that her apparently kind husband was a sleazy cheater, we’d have an age-gap yuri romance. (The story would still have to deal with the age gap somehow, but there at least seemed to be the outlines of a potential path to UxK.)
But at this point not only does that path seem to have disappeared, but (to me) Kaoru no longer seems like a worthwhile partner for Uta in any case—for a variety of reasons, she seems much more self-centered and in fact rather dim-witted, while Uta has become more self-aware and mature in her thinking and actions.
The writing and plotting in this series is such a muddle that hypothetically it could certainly take a turn toward getting Uta and Kaoru together somehow. That just doesn’t seem like such a desirable outcome to me anymore.