Through the letter that Key had written, we can see all the memories that he has stored - them being played, expressed, and finally, finished.

I had this idea through an emotional event. Today, I found a bird in my garden, and it had just dropped out of a tree (I assumed). It was a newborn, meaning that it didn't have any feathers, and the eyes weren't even open. We looked around for the nest but there was no sign of one. My family and I tried to save it, but however, we discovered it too late and there was nothing we can do.
R.I.P, that poor bird. May your soul rest in peace.

Warning: Angst and character death