Great Acting and development of the characters but the best thing about the series is it is well written, a little funny in parts and never boring ... the plot is woven well and usually quite serious, very fast paced. The leads and the secondary actors r well chosen for the roles .. i personally enjoyed it and wished they had a second season. What i love about korean series is they do not use repetitive formulas again and again like hollywood! The plot and subplots are original yet realistically presented without too many coincidences etc to help make it work ... the dialogue was cool even when cheesy it was delivered in a light and cool way with the actors able to laugh at themselves ... i strongly recommend it.