The leads were very good, and the dorama itself had its good (heck, even very good!) moments; unfortunately, that was partly ruined by the many obvious, repetitive, forced or plainly silly scenes whose only "raison d'etre" seemed to be to stretch into 12 episodes what could have been much better developed in half the episodes or maybe even in a tv movie. Ironically enough, for a drama which focused so much on missed opportunities, that's exactly what it ended up being, imho: a missed opportunity.