Doesn't sit so well for some reason...
This is weird. Like for instance the guy is left heartbroken after the girl left him. There should be some level of resentment that he wasn't enough for her in some ways. She leaves him for another, which readily appears to be much more awesome than the male character. This would leave the male broken in a lot of ways if they really cared for the other person.
I guess there's some understanding for the fact that if the girl was female, she hasn't really experienced too many things. And again I'm assuming this is a young relationship. When she doesn't really have a real scale to place good and bad on. But still, there's something unnerving with the male accepting her back into his life. There's gotta be a giant shot to his well being understanding that this would happen. And its one of those things that's almost impossible to heal unless he did the same to her at some point and came to the same reasoning.
I'll say decent job with the animation. Like it, music went well with it. Story and concept though, I pity the male character very much.