This show is actually a remake of a Turkish show called Kalp Atisi (Heartbeat). I think the reason why the Korean remake is so good during the first few episodes is it's actually identical to the first few episodes of the Turkish version. The Turkish show itself was actually very good and unlike the Korean remake did not make me drop it after a couple of episodes. Although the Turkish version's plot does die down towards the later or second season it was actually still very good. Personally, if you think the plot sounds good then I recommend watching the Turkish version over the Korean remake. It'll make for a much more thorough story and also the growth of the characters is more well depicted.