Beyond Evil

Both involve two men where one seems very suspicious and the other is convinced he is a murderer while you as a viewer is confused about whether or not he can be trusted. The dynamic is just similar. TSHLYE is romance-focused, though.

both explore trajectory of lives of people who has encountered psychopaths and pain that they have to carry for rest of their lives

Comedy version of "i think I'm a psychopath killer"
While waiting for the serious genre, let's watch & have fun with yoonsiyoon/donggu drama. You won't regret it

To My Star 2 was filmed in the same area which Beyond Evil was filmed?

https://twitter.com/oriionpaxxx/status/1536493599608774658?t=2Hk79jENA7CEQf_gaVyCwQ&s=19

Also, yearning, rural life/people and 'investigation' may be counted as similarity, too

Both shows feature morally complex characters who make difficult choices in the face of impossible situations. The protagonists are not inherently good or bad, but rather driven by a mix of good intentions and self-preservation.

Both shows create a tense and suspenseful atmosphere, keeping the audience on the edge of their seats as the plot twists and turns.

Both has two main male leads. Both are thriller, detective, suspended drama. Adrenaline action pack. You won’t fall asleep on this kind of drama.

Both dramas have protagonists who may not look very upright
Both are police investigation type dramas
While Beyond evil focuses on many criminal cases, Connection focuses on cases which are connected to each other
Both have plot twists which keep you at the edge of your seat!

mystery shenanigans. detective plot. great development of plot hahahaah, so like basically der r detectives in both shows. seriously i can't explain anymore, but I'm pretty sure you'll love beyond evil.

Both set in a small town village with a crime case to solve.
Both with deadly secrets uncovered.
Both has great acting.

The japanese version "Kaibutsu" is a remake of the Korean version "Beyond evil" , so the story is almost the same with a little difference in characters.

A layered plot with a side of mystery that's slowly unraveling as the show goes on, they are both set in a small town with interesting and morally grey characters. While the genre is different, both shows ask the question: How does your upbringing shape you as a person?

ML also plays a younger version of the main character in this. Also, they have the same director.

The main serial case in both dramas have a lot of similarities, in which it may be based on the same murder case that sparked many different dramas and movies based on it. In both dramas there seem to be some hidden conspiracy which lead to people attempting to cover up the murder cases and led them remained unsolved.

Policeman, a remote village ,old mystery, budding friendships, -- although the backdrop and the story are not same, somehow the vibe is similar.

A murder takes place in a small town. As the story progresses, entangled in the lies and crime, community members start to show their true colors.

Both sungmin and hakyung are amazing actors. They bring tension and their characters to life
Both dramas are also extremely tense crime dramas