ahh yes, I do not need to read this manga as long as these comments will give me a better idea.
Chizuru just has be his Girlfriend, marriage or not they can always break it off later on when Grandmas eventually die,
I mean is being someones Girlfriend that hard in Japan? of course you have to pay your part with both feelings and money at times but its not that bad.
or is it because Chizuru wants to keep her gig going as it pays her bills and our MC doesn't have the gonads to ask her to live with him or something.
its not a problem at all,
or as it all goes down to, Author want Rental Girlfriends forever.