"Having friends, getting close to other people. I always thought that there was no need for me to have such bonds that would tie me to other people. But after I spent that short time with you, I realized how much I craved the warmth of another human being. Now that I had experienced it for myself, I did not want to return to those cold days again."
That was why when she met Nagawa Sano, it all worked out for the best.
She already knew from the very beginning that this person did not love her, but that was fine. It was okay this way because she did not love him either.
The reason she was so devastated was not because she was attached to her feelings for him. The thing she was attached to was having somebody by her side who trusted and believed in her. Even if she could never bring herself to love him, at the very least, she thought he would be a companion that would never leave her side.
To think that even that companion would end up betraying her.