For starters, this drama has many characters apart from the main leads (you can already tell from the poster). I believe The Heirs became popular due to it's cast, many with Lee Min Ho, Park Shin Hye and Kim Woo BIn as the leads. In addition, many of the supporting characters are kpop stars as well so definitely a good looking bunch of people in this drama. If you're looking for eye candy, this definitely is a drama for you. The central plot was not really developed but we are able to get the gist of the story. As for characters, I think Kim Woo Bin is the only actor that stood out for me and I believe he successfully portrayed his character well. He truly gave me SLS, and character growth was excellent as well. In fact, I would say that the sole reason I managed to finish this rather bland drama was due to Young Do (KWB's character). Lee Min Ho and Park Shin Hye were OK, cute moments were fluffy but nothing made me swoon. Acting was generally okay, just that, like I said, character development was lacking. At the end of the drama there weren't satisfying resolutions for most of its characters, which I believe is due to the fact that there are so many characters. Hence, at the end of the day, this drama delivers cute moments, your typical high school drama and solutions that were not really meaningful in resolving the major plot issues.