This was the most perfect short story. It has a little bit of angst but nothing really serious that can help the main couple from achieving their happy ending together. I loved how the marathon culture is around them and how they were getting together little by little, in a way that was amazingly sweet. Maybe Mr Heart is not the most complex story ever written, but it is fresh air if you compare it with other heavy-based typical plots over there. And of course, the fact that it has a happy ending is over the top. We need more happy BLs! I totally recommend this drama.