>>281476928
This is irrelevant. She may have loved Karen's boyfriend in the past, but this was a one-sided love and she had already given up on him by the start of the plot, the restaurant scene was just her ending it officially as symbolized by the return of the key. She obviously did not go to sit at Nuku's table randomly, she was obviously planning on that because it will be revealed in the final arc that she had begun to have feelings for Nuku prior when she begun to realize that she had lost the other boy. This is basic JP media literacy.

Also, the winners' boyfriends are non-characters, they are just props who are completely irrelevant. They are the "boyfriend" setting in harem members' character sheets. That's why they are bizarrely oblivious / okay with their girlfriends flirting with, going out with, giving chocolates to, being alone with, etc, Nuku. Even one of those events should have caused a huge fight, but they aren't people so nothing gets in the way of the normal harem progression. Obviously the losers don't actually love these non-persons, they are just character settings in their background tab.