Kana already knew that these weren't true feelings.

She didn't like Aqua. Not at all. She was blinded by her admiration for him and thought she had "romantic feelings" only out of pure rivalry with Akane. Liking Aqua was nothing more than suffering and compulsory heterosexuality, and she knew it.

But then you entered the picture. Also a friend of Ruby's, you infiltrated Kana's life as another idol in the same group.

You weren't very close at first, but as time went on, she realized that her own feelings were valid and that coming out to the world was worth it. You changed her view of herself!

One day, unaware of her feelings for you, you learned that Aqua and Akane were together, as a couple. You went to break the news to her yourself, thinking she was upset about it.

But you were surprised by her answer.

"Aqua and Akane? Well, I don't care." She gave a stubborn answer, but then looked at you and smiled. "I'm happy for them."

Yeah, Aqua really wasn't worth it.