Recommendations

both kinda talk about the work environment from a newbies pov. in both they go through alot of tension and struggles trying to understand the dynamics of a not so perfect and suffocating block that one can't easily fit into

Both are fantasy ,romance ,drama that take the parallel aspect well executed;while extraordinary you is school ,parallel love is about business and
the main couple is older .

I have watch the previous seasons. I hope you can still find a way to put back LEE JIN WOOK in the lead role for Season 4. He justified the role very much and it went as very highly anticipated series. He has the very strong appeal to make the series very commendable.
Why not make a twist. You have shown that he died but can you make the story like he only had a near missed shot, a grazed shot in which he survived at the latter part. You just need to show the world that he died and sent him off because he needs to catch the real culprit. Then add the romance together with LEE HA NA to make the viewers more alive. If that would be the ending, it was very sad and I wouldnt want to watch anymore the next season because of Lee Jin Wook and Lee Ha Na. He should still remain as Do Kang Woo to finish as what he started and to be involved seriously with Lee Ha Na. They do have a great chemistry.
I find Song Seung Heon too old or matured for the role. I would still prefer Lee Jin Wook if possible. Please make it possible for Lee Jin Wook.

Both dramas are about a normal world suddenly being swept with a virus that turns humans into monsters. Packed with suspense and horror, if you liked one you'd like the other.

One of the main plot points in 18 again is the dad attending his children's school as a student and helping one of them against bullying. That is exactly the same premise in Angry Mom; a mother finds out her daughter is being bullied at school and ends up enrolling as a student to make sure the other kids stop.

The feel is kinda similar.
Also both are quite dark and has a few deaths in them.
There's a male lead that has some kind of power that makes them special and able to fight against the ...whatever's evil.

Similar vibes on long-term dated exes who meet after years and work together at an architecture company.

I don’t want to be friends with you is much more complex than this lovely us but they both have similar themes — growing up, friendships, family, love stories that last a life time. They are both dramas that leave you feeling warm inside. I don’t want to he friends with you surely makes you cry a lot more tho but don’t worry it ends well <3

Yoo In Na is also the female lead. The ex husband also comes back into the picture. The plot is also disappointing. Different plots but there is also a murder mystery.

both films are about Japanese fear and hatred of foreigners invading Japan. In "Kamikaze Taxi" the xenophobic behaviour is directed towards nikkei (the male lead is Japanese-Peruvian). Both are about yakuza and power struggle as well.

Both shows deal with mutated monsters for different reasons, and time is running out. Also, both shows work with jump scares and horror motives.

At the first few episodes of 35 sai no shoujo, I was reminded of "Thirty but Seventeen," but as the story unfolds and the attention was on the family, it reminded me a lot of "My Unfamiliar Family".

Story wise it is a bit different (a family member's accident affected the whole family can be a common factor though) but the vibes and the focus on family was what reeled me on both dramas.

i am surprised no one recommended Vampire Detective yet since the feels are so similar compared to other recommended dramas here. Yoon San and the vampire lady has the same energy as The K2 and his lady boss. in fact whenever Lee Joon fights off the bad guys, his action skills really reminds me of Ji Chang Wook. Lee Joon is such a hugely underrated action star!

Arisu—a listless, jobless, and video-game-obsessed young man—suddenly finds himself in a strange, emptied-out version of Tokyo in which he and his friends must compete in dangerous games in order to survive. In this strange world, Arisu meets Usagi, a young woman who’s navigating the games alone. Together, they set out to unravel one mystery after another as they risk their lives and confront what it means to live.

Both are survival show

Both are Thai BL dramas with a lower budget and quite underrated but still enjoyable to watch between other series. Plus, both of them have some good LGBT support moments that I really liked :)