Well... this one honestly felt lazy to me tbh...
Sure, it's for the most part the usual Atelier Sakura set-up for this sort of thing. However, the problem I have with this one is just how inconclusive it is with its endings. Regardless of which ending you pick, the game doesn't really dive into the consequences of those choices.
Allowing Mayumi to go on the trip to France has you see one scene from her perspective where she's still fucking the guy, with the implication that they're doing it there a lot... but it doesn't actually dive into whether that has any consequences or not.
The only difference really between the endings is that in one ending she fucks with the guy a lot and in the other she only, presumably, fucks him only one more time. In neither do they really dive into anything. Sure, in the ending where she doesn't leave on the trip they show that the hubby and wife fuck like rabbits every day, but we don't see Mayumi's thoughts on things and we don't know how much she enjoys the sex or the situation or anything. So for all we know, she could still be cheating while her hubby's at work or something. Likewise, nothing says that they couldn't go back to normal after the France trip either.
Granted, they made a sequel that will cover that, but the time between the two releases is a little over a year... and with the pace Atelier Sakura releases stuff, it's pretty clear that the sequel wasn't planned when they originally made this. They just did it because there was a demand for it, so the story was left on a lazy note from the get go.
Oh well, at least the scenes were decently hot, even if Mayumi's expressions outside of the sex scenes were a tad weird at times... Where the heck is she supposed to be looking lol? XD