Her name is Haushinka, she's just a girl with an unknown way to path. She's a girl who doesn't know what to choose, what to do, what to feel, what to say.
Haushinka is a girl who loves to live her life to the extreme, she doesn't care about anything but herself, and she's right. Because that's the only way to be happy. You can't keep yourself from your feelings just because you don't want to hurt someone else. Haushinka knows that. That's why she's happy.