Aki is unfair. It's not because Himari would eventually reject Yori that Yori would automatically go out with Aki later. First, she didn't confess, but if and when she does, she will put Yori in the exact same situation Himari is. She wants to be the one to "make Yori happy", but she would eventually make her miserable. And she's putting the pressure on Himari to reject Yori for her own selfish desire when she doesn't have the courage to confess.
Himari is unfair, because she makes Yori wait. But it's not like she has to answer to Yori's feelings right away.
Yori is unfair, because with her confession she put the pressure on Himari to answer positively or hurt her, which Himari obviously doesn't want to, because she likes Yori (romantically or not is the central question there).
Love is unfair and selfish, alright.
^Sex between women exists. Fact of life...
last edited at Feb 8, 2020 5:47AM