I am a big fan of well developed mysteries/thrillers. There is just something to them that keeps me glued to the screen.  But I have hit a point where I cannot find dramas that fulfil this.
Thus, I'd ask you for your help in recommending me well developed crime/thrillers from China, Taiwan, Japan or Thailand.

What I like look for;
- gripping cases,
- characters that are older and flawed,
- "moral upright" people turning bad (especially like this aspect)

(Some dramas that I truly loved with these aspects;
Taiwan - Trinity of Shadows, Not a Murder Mystery, Victim's Game.....
China - The Burning River, Burning Ice, A Murder Mystery in Horizon Tower,.....
Japan - A Mignight's Equation, Aku no Hado, Kesenai "Watashi": Fukushu no Rensa...)

Of course if anyone can also think of a different drama from a different country to which these things also fit that I am very grateful for that recommendation :) I am just sceptical about korean productions. But apart from that any recommendation is welcome!

Thank you for your help and reading! 

I remember:

Border (A police detective who can see ghosts after a bullet lodged in his brain, uses this advantage to solve cases-but the lead is slightly young)

Love Me if You Dare (A professor who learn the psychology of the criminals-like Criminal Minds-is helping the police solving cases. For 'moral upright', not the lead but the hidden villain)

Edited: if you like this, you could also try two another of drama adapted from Ding Mo's novel: When a Snail Fall in Love with Wang Kai dealing with bomber I think, and Memory Lost with Bai Yu dealing with drugs syndicate if I remember right.

Mouse (Two male detective leads, one young and one old trying to solve serial killer case who copy the previous serial killer who's already in jail (if I remember right). One of them 'turns' bad but then atone his sin)

Signal (Can't quite remember the detail but I remember it's so engaging back then, the leads live in different year, they communicate through phone (perhaps) to discuss unsolved mystery)

Under The Skin (A painter helps the detective to solve mystery by painting the portrait of the criminals based on the description told. He atone his sin because back then his painting was the reason one of the previous criminal found the victim)

I hope you like them.

Just throwing some stuff that I really enjoyed that you might like (I think none of the protagonists in these dramas can be considered truly "good", more like some shade of grey):

@autumn Iris
thank you for your responds. I have seen every one of these dramas. Signal is my most favourite one so very good choice :) I am not a fan of Ding Mo's novel adaptions sadly. I did like When a Snail falls in love however more due to it cinematography than due to it's storyline. The novel is well done though.


 kura2ninja:

Just throwing some stuff that I really enjoyed that you might like (I think none of the protagonists in these dramas can be considered truly "good", more like some shade of grey):

thank you very much! I have actually not seen any of them I believe so these will help immensely. 

Checking your list and thinking a few you haven't watch and may like:

Juvenile Justice

It had the same actress on Signal. Fl lost his son but receiving insincere apology from her son's killers and then they soon be released because it's their first offense so she decided to be the judge of juvenile criminal case and giving harsher punishment for the criminals (and doing some bad things like manipulation and lying).

Killer and Healer

A police officer and a doctor work together to find the drugs dealers. The police does a few things out of boundary just to catch the big fish, e.g. changing side, shooting his friend and so on. But you might want to see the trailer first 'cause it's a Chinese normal drama with 37 episodes.

Ouroboros

2 ex-orphanage children try to find out their caretaker killer. 1 of them enter the police, 1 of them enter the mafia. They exchange informations and work together to solve the mystery.

The Chaser

A man (probably a detective) tries to find out the mystery around his daughter's death, not knowing it involves political figure so he met with many obstacles and even get fired I think.

Unnatural

A forensic team help solving the various cases through autopsy. One of them is actually a spy. Very unique.

Possibly...