I can't get that "Kanako". So, she has feelings for Ayaka but she could have sex with her senpai just because senpai said "i love you"? did she really love anyone at all or just a slut? I can't stand that kind of character.
Btw, I don't think this story have anything like "cheating".
Life isn't all about love, there are lots of other factors at play. People don't always end up with people they love. A lot of the time they just say it because they are too ignorant to realise otherwise or they need justify it somehow. So maybe she didn't love senpai and senpai definitely didn't love her. But that doesn't make her a slut. She's only desiring and sleeping with one person that she already trusted and admired, isn't wasn't some random person off the streets. I'm sure she loved the other girl but not in that way. Someone else offered her what she wanted so she took it because there wasn't a reason not to. Of course I'm not saying she's not f****d up, any good character is.