With how transphobic the students at this school are, I can only guess that they treat gay people similarly.
Time to predict what happened between Yukka and her crush. Considering that Yukka dragged Hime along with her under the pretense that they were only going out to eat, Yukka seems to not handle her own issues directly. It is suggested through her conversation with Hime that she has developed an understanding of how people see herself, and how she views them. This is reinforced by her comment on the intentions of the older track girl, but this instance also hints that she does care about the opinions of others. All of this depicts her as self conscious, and, given that, how would someone like that pursue someone they like? We do know that things don't turn out favorable; she ends up binge eating. My guess is she becomes friends with her, develops feelings for her, indirectly asked her crush if she was into woman, and found out she wasn't.