You mean the wife he doesn't care to satisfy?
i am not so sure about "satisfy" we have seen her and the husband bang soo many times, sex intense enough that MC hears it on his room, up until now the husband is just your average Japanese salary man who's is always busy with work and don't have much time to spend doting on his wife either because of not being home or being tired, he still fuck her whenever she ask for it.
she's missing the flame of a new couple, the doting, the affection, the energy, the effort, all the things that give you the fuzzy feelings, those things tend to slow down after some years of a married life, daily life tends to get monotonous, its hard to blame the guy, that is until we find out the the reason for all of this is because he bangs some side chick on his "work trips" so doesn't have the energy to invest on his actual marriage
