Love the "koto has changed" line because like it's clear that Aya has a moment of "what? changed? no?" but from Erika's perspective Koto probably spent seven years depressed/just kind of wandering through life and now that Aya's back Koto has changed back into who she used to be.
Which is good from Erika's point of view because she's doing better than during those seven years and it's giving her the ability to actually process her feelings for Aya and put an end to the part of her that is still in love with Aya. But then of course since we've seen Koto's perspective, it's not looking she's processing her feelings for Aya in a healthy way even now that she's getting the chance to.
Also with how the chapter ended on Aya thinking to herself "and Koto's also in love with me" I'm starting to dread when Aya will start to realize that that love has become rather obsessive. lmao