the drama started so well with interesting crime and i think making it so obvious and make us search for the killer with the lead was a big plus to enjoy the show, the characters of the 4 main kids on school was all different and interesting and tbh the best thing on the drama was those kids and their acting what make me enjoy the show! and give it high rate they are the discover especially Beom Jin. i hoped the writer will focus on their stories more.

however around the late half the writer get lost and change all what he build and give us a lot of the adult unnecessary scenes and not to talk about the annoying female teacher her character was just pain and stupid from the start to the end. if they cut her down the drama would be better.
i loved the male character but the sudden move from going with facts to take the lead guesses as evidence what kill the drama. like how he suddenly focus that xx is the killer and start to make image to it and it fit well!! and yes that's it. like what?!!! just because his character fit well nothing more that strong.
and what with the ending!! are this really ending ?? i don't know what the point of that.

what make me give it high rate like what i said before the start, the 4 evil kids and Yoon Gyun Sang. it wasn't boring and it drag me to the end even though they end it poorly.