So the poster and the genre categorizations really fooled me into thinking this was a rom-com. While there were a few humorous scenes, for the most part this was a full on drama, with mostly serious plot-lines.
Kang Min-Ho has a serious heart condition, and after unexpectedly receiving a donor heart, he begins to change - is it because of the heart or the people around him? This is the core story line, and it is done very well. I loved how Min-Ho changed gradually and in a realistic manner that didn't feel like he had a totally different personality. I also liked how for the most part they were realistic about his medical condition, with him having to recuperate in the hospital after surgery instead of bouncing back right away (which is an irritating pet-peeve of mine).
Jung Kyung-Ho really shone in this, with Yoon Hyun-Min doing a great job as the rival/villian. The FL was fine, I liked her but she didn't particularly shine in any way. Easily my favorite character was Min-Ho's male secretary Woo Sik, who was lovely, loyal, funny, and sweet. The bromance scenes were the most enjoyable of all, even over the romance for me.
As a side note I really wish Min Ho had kept that long red hair throughout the series, it was seriously a LOOK!
