THIS DRAMA IS A MUST! Don't be fooled it is one of the best drama this year, dunno why it is over-shadowed by Oh My Ghost,She was pretty and Kill me,Heal me In my opinion this drama is above those. I really enjoy watching dramas flooded with love lines between the mains and especially those where the relationship and the storyline is not overly-done or cliché-like. But SWEET JESUS this drama was the first drama where I thought the love story between him and her was unnecessarily and burdensome and that the plot and bro-romance needed more screentime. She was nerve-wracking (both her as an actress and the character she played imo.),she made me skip most of the love interaction between the two leads (lucky that it weren't many of them :)) ). Seo In Guk was alright I'm not a big fan of his acting (althought I enjoyed how he played in Reply 1997) but damn his facial expresions were so on fleek, in some scenes I really thought he was a psycho-like character or either that he has an unnexpected secret in his sleeves soon to be discovered. My petite new crush Park Bo Gum was so cute and handsome too,his acting was good also,same goes for D.O and his older self Choi Won Young. The casting was awesome but I have a minus for the main female cast. The plot is quite unique and I really cheered up for the bro romance to have more relative screen time.I enjoyed this drama and I recommed it to those who like mystery,detective and action oriented dramas.