The first three chapters are a lurid but pretty varied "lets do a tour of parts of the body not traditionally considered erogenous" and thus has some novelty to it, paired with the emotional subtext of two people playing chicken with physical intimacy, trying to be on top, and admitting their feelings.
4 and 5 are just feet all the way and reminds me why foot fetishists are so exhaustingly boring.
Incredible, it started with a great story, absurdly high-quality art, and a cute yuri plot, and then it turned into NTR crap that doesn't even make sense.
I honestly think it makes absolutely no sense to combine these two stories.