Signal (2016)

Right from the first episode onwards "Confession" gives off a "Signal"-like vibe.
We have 2 very similar male leads, with a nearly exact personality and background, a team that is as similar as can be, characters and even storylines that are very similar to each other.
If you have enjoyed one, there is a high chance you will enjoy the other.

CONCEPT
- Portrays changing one's fate that could lead to a harming effect
- Has connections to the past period but a different aspect

Signal is my representative kdrama in the thriller mystery genre, and Tell Me What You Saw gave off that vibe, also the start of the 1st ep really reminded me of signal too

Both are crime series & though the story might not related at all, it gives you the same feels: goosebumps & keeps you sit on the edge of your seat since it's full of suspense & unpredictable twist and turn. You won't regret watching this, it truly is a masterpiece.

If you're looking for another crime drama. This is the one! Signal is more of a thriller, while Missing noir is more of a Twisted mystery Drama with Thirller and suspense sprinkled on top. And by twisted, I mean dark and well thought out murders that are memorable to me to this day. They take leads from very small evidence which I couldn't have thought of. Very unpredictable. Side note:There is no supernatural element to it so its pretty realistic

Both mysterious and thrilling.
Both have a way of changing the future, where in 'Signal' is through communicating in to the past through a walky talky, and '365: repeat the year' is by going back exactly one year.
There are also detectives as leads in both shows.

While this movie is about a husband talking to his dead wife, Signal is a drama about a young detective using an old walkie talkie to communicate with a detective from the past and solve cold case murders.

-Both are crime dramas
-Very similar vibe
-Both follow the main character (who is a young rookie detective, still holding onto his dark past involving the police versus criminal-minds-esc bad guys, and because of this he often lets his emotions control his actions and judgement) and the other characters on his detective team while they work to solve many major crimes and cases (roughly 6-8 throughout the season) that lead up to solving a major case
-(Signal works with cold cases and Hidden Identity just works with cases revolving around a mysterious person named "the Ghost")
-Both feature 1 badass female on the team who's past is also dark, mysterious, slowly revealed throughout the series, and affects her judgement (although less than the past affects the main character)
-You fall in love with every single character on the team - no matter how small their roles
-The dramas do not shy away from tragedy, violence and heavy/dark plot twists
-There's always that "there's something else going on here" vibe
-THE PLOT TWISTS THO. ... yup. Imma just leave it like that.
-The acting is INCREDIBLE. You will cry. Multiple times, probably. It will hurt. But it is amazing
-Both make you wonder, "what kind of sick, twisted, brilliant, talented person could come up with/write this plot??"
-No romance... (technically)... Trust me, you don't need it.

Both are crime/investigation/Detective dramas, and both are so very complex and twisted that they leave one hanging at the edge of the seat. Absolute amazement.
There are a few more similarities however due to potential spoiler reveal I cannot name them. There is however a high chance that if one liked the one drama, the other one will appeal as well.

- both shows like to switch between past and present to gradually reveal the events that led to the current situation and to uncover the mysteries related to it (the use of sepia/yellow filter is also similar)
- there is a lot of injustice happening around the main characters and it's very difficult if not impossible to deal with it
- both shows are consistently dark throughout all of their episodes

I'm pretty confident a fan of one will like the other.

Signal although is based in different cases, there is one case based in tha infamous Miryang case and if you're interested there is Han Gong Ju another dark movie about the same case, I recommend you to watch both the movie and this drama you won't be disappointed

Both involve detectives and time travelling. The mystery unfolds slowly, while keeping the audience on the edge of their seat with each episode. Parallel worlds infused in science-fiction and the genres of crime and thriller. If you liked Signal, you might greatly enjoy Alice.

The chemistry between Lee Je Hoon and Kim Hye Soo feels similar to Joo Ji Hoon and Jun Ji Hyun, the female sunbae teaching the newbie and working together as a team. There's also mystery in the plot and we have different cases in every episode.

Both dramas deal with a mysterious storyline with a great ensemble cast and acting. The stories are top notch and effectively delve into various genres while settling with the main story idea. Writing is phenomenal and cinematography is somewhat similar because of the tones the two dramas carry. Actors really excel in their work and transport you to the scene of the situation.

Both male leads are in contact with someone from the past and exchange pieces of information with each other through a specific machine. The big difference between these two is that they have completely different genres. Signal has little to no romance and focuses more on mystery suspense and crime while ditto focuses more on romance. Signal IMO is an outstanding drama, please do watch it if you have time.