Favorite plot twist? Episode 5, "The Sunlit Garden - Finale"

This whole time we've been hearing Miki's version of events, that the piano playing in the garden was some beautiful, peaceful memory to be cherished - something pure. Not to mention all about his guilt for failing to come through on the promise he made to his sister about their big concert. But then, in the last few minutes of the finale, Kozue comes outta nowhere and tells one of her friends about how, and why, she learned to play piano.

You get the feeling that Miki never really knew what was up.