Awesome. Just happened with Kimie, too. Was at 2 stars, I gave her gifts to get to 3 stars, clicked the upgrade button and now it says I need 1105 more affection points. Wiped out 500 affection points I gave to her, and doubled the amount I need to get to 3 stars.
Did the required affection change in this patch, or is this just a bug? Possibly both?