It's expected, but the "Don't leave me" part made me feel really sorry for Hina. In the end, Airi's still just a narcissist, and never love Hina. She even didn't want them to suicide together at the beach, but murder-suicide after that. She's selfish till the end. It's good, it didn't have a climax to make me suffer strongly like feeling sad, angry, but it had own ways to make me feel empty and lost. I enjoyed it, althought something didn't satisfy enough. Also, hope the Ichika girl get the glass girl some karma.