Dunno, I think this chapter was a bit random/out of place after the last some chapters. Even more so after reading chapter 57.5 directly after. Satou instantly being with another girl when she made up the promise herself, Makino instantly jumping ship (well, Satou is pretty much keeping her as a plan B and she kinda knows, so not really "jumping ship") and everyone just being insanely selfish after having had a moment of.. clarity? I suppose it could be called.
Feels like this chapter was done to honor the name of the manga and have it be relevant again? But made it feel like the past 4 chapters had zero impact and the development just poofed? But the again, it DOES stay true to its roots so... I guess I am confused on what to feel
I think it fits. The promise was about Makino not going through with these marriage interviews but we know that Makino is easily distracted and foolish. So her falling into a trap of her own creation makes sense. She still thinks she's doing it to get closer to Mashiro.
Mashiro also never promised nor even mentioned that she'd stop doing her "side job" and Makino knows this already. They even discussed her schedule last chapter. So unless the criticism is that her job is inherently wrong or something, the two characters are fine with it and see it for what it is. Makino doesn't seem to be bothered by it and Mashiro clearly views that stuff as part time and temporary work--a way to make much needed quick money for the time being to pay for college, etc (not to mention her abandonment issues). They're both consenting. She also clearly views her relationship with Makino as something separate, romantic and exclusive. So I don't think Mashiro is doing anything weird and definitely isn't keeping Makino as a "plan B." What would be plan A?
The only plan she has is that she doesn't want Makino to get literally married as that is clearly different (emotionally and legally) and much more permanent and hard to separate from after it's done. A few chapters ago Mashiro was about to answer Makino about her intentions to date. She's clearly looking to make them official, hence the promise. She's already had reason to worry about Makino's scum tendencies and her obsession with "Maron." So this promise
should have been a simple "health test" to pass before dating...They both have made their boundaries clear to each other. Only Makino has then decided to step over that boundary for money, which she really doesn't even need to be with Mashiro--as opposed to "Maron." But she's "scum," so of course...and it'll bite her in the ass.