You could tell exactly the type of person Yoshino would be just from reading the first chapter of the prequel to this manga. An empty shell of a human being who couldn't even imagine an existence outside of being a corporate drone in Japanese society. Her tirade about how she was overcome with rage because fellow students in her middle school had dared to speak out against authority and staged a protest over not being able to wear casual clothes was the least surprising bit of dialog to ever come out of her mouth. This portion Yoshino's arc was very well done. The author is clearly familiar with this type of awful person in real life.
Anyways, Yoshino and Akio's relationship had zero intimacy or chemistry outside of sex (and even their sex life was shaky). They were very clearly only a couple for plot's sake. Akio spent the entirety of this manga and its prequel moaning about how much he did not want to become a salaryman like Yoshino wanted him to, yet he was somehow still deeply in love with a woman who represented every disgusting aspect of corporate drone society in japan. Yoshino is a product of, and a purveyor of, that stern, soulless Japanese conformity and "the nail that sticks out gets hammered down" mentality.
At first I thought the Akio x Yoshino pairing was meant to be ironic and that the message would become clear in the latter volumes, but that never happened. The author simply did not know what to do with Akio or any of the supporting characters. So that leaves us with Yoshino, but just when you think this manga is going to expand on or challenge some of her views instead we get Akio just nodding along with everything she says and then the next arc is a really shitty melodrama about that old guy Yoshino fell in love with and his wife.
So like several other reviewers before me, I was left wondering what the point of this manga even was. It is not a good or realistic depiction of relationships, it is not a good drama and it is not a good thematic story because it doesn't actually have anything to say wrt said themes.
Guess I'll just chalk this up to being a very early and bad work of an author who had yet to find his voice. Read Genshiken by this same author instead. He actually had something to say with that manga.