Hello monster is very well scripted and brilliantly acted series. There is never a dull moment, just grips you in. This is NOT just any other crime drama with stupid cases and cheesy romance, it actually delves deeper into criminal psychology and how childhood trauma or the way society treats them could trigger a person to transform into a beast.
Things I absolutely loved
1)Every case they solve reveals a minor aspect of the main story line, which makes it quite interesting.
*~SPOILER alert! -'*
_ like in ep 1 the killer thinks he is actually killing the same person again and again like min does ' .
_And the one in which a guy ( son of a rapist) is always traumatised by the fact that he would end up like his father. But dies saving someone else heartbreaking.

2) Villains having an origin story ( very rare)
_Like I know why Lee jun young is so hell bent on rescuing children from abusive homes murdering their parents and min targetting people who abandon.

3) Female lead is super strong. Really! -Refreshing. Kicks ass, doesn't wait to be saved, emotional anchor for ML though herself dealing with tragic stuff. Does what is right and knows when to do it. I loveee Jang NAra!!!!
_one scene where she is gifted the location of her father's burried bones on her b'day aaahh h!! she waited for it for 20 long years that she couldn't shed a tear(on the verge of total breakdown.)

4) Seo in guk is a gem! ! Especially during the case profiling and interrogation scenes. And a super adorable hyung.
5) PGB is a revelation. I like how his eyes turns from lost puppy kind to total creepy within seconds.
6) The team. Sunbae leader kang everyone.
_ leader kang is a nice kind of second lead harbouring a secret crush, protecting but NEVER. clingy.
7) OTP - cute ,caring ,realistic ,share gloom.

Things I found irritating:
1) all of them having meals together again and again. Knowing everything!
2) while min heads to confess other the real murderer set loose. so much time to arrest wasted !!
3) no scenes of Lee jun young brain washing Min as a kid .what happened in those years.
~END SPOILER~
Please watch it! keeps you hooked. Very unique and underrated.

Read More