This was one of my greatest drama dissapointment ever !!!!!!!!!!!!!!!!!!!!!!!! Watching ep1 was truely terrific !! It made my expectation rise.... perhaps i had too much high hopes for this one (-_-;) that upon finishing this drama, dissapointment was enormous (T_T) What i liked : = Excellent idea of the story .... the plot was fresh !!! (don know other drama having similar storyline) , it was intigruing ... got me reveted in no time n it was unpredictable largely = great acting by teen twins (good job Park hyung sik !!! ) n other characters = creative way of storytelling .... each episode projected a little bit of experiences that the twins went through... which shaped their respective personalities to adulthood ..... and this help explain their change of behaviour ..... but it was done little by little ..... so kept me guessing as well as gave new insights to the character's personality What i disliked : = main actor Suh Joon Yong's acting .... it was okay until these brothers got swapped . I can understand that the story needed the viewers to b confused over the twins , but even so i cudn't find any demarcation betwn the elder n younger twin ..... the brothers were supposed to have completely different persanalities but he acted same to same for both ones when they got exchanged = Irresponsible n incomplete plot .... while i liked the story idea, till i finished watching found plot mismatches here n there.... i cudnot help but getting the vibe that the makers were a little bit careless only giving attention to ill karma between the two brothers.... = lack of character development ... well,, this may b greatly bcoz of so few episodes even then this lacked a lot in character development for me =Time n Event relevance ..... it was very difficult to understand the flasback's time order (what i mean is, which scene happened first ?? for eg . was the visit of mother in jail was before she got addict with drugs or was it after ... ) = the ending .... first i will make myself clear that i am not biased with happy endings or any other kind ... Its ending was Sad, Unclear n Pessimistic...... it wud have been better if at least they showed some downfall of drug world So all in all , despite having a promising start n great story , this was a huge dissapointment. I wud not reccomend it proactively, but for entertainment purpose only its worth watch once for .