My guess is Riri gonna drop out of college to pursue modelling, hence why all the "one last favor", "just want to spend time with you, slowly" and the souvenir to remember those short, gone-in-a-flash days by.
I'm thinking the same thing ): noooooooo my 2nd fave after Maria is gonna be taken out just like the rest (*꒦ິ꒳꒦ີ)
interesting, now that her true intentions are revealed, wonder how that's gonna go. Doubt Kuroiwa will fall easily, maybe Mashiro will be the one to end up falling for her instead, and will get hurt along the way.
this fits so well with what happened in the anime, I did wonder what was going through her mind when she was staring out in to the ocean alone in the dark.