Recommendations

Both are dealing with serial killers though Signal has a Sci-Fic element in it.
Both have action, suspense, thriller elements.
If you like Signal, try Inspector Koo and there is good chance you would like it.

Both these contemporary dramas are sequels of period dramas.
The common point is that the main leads features in the dramas are reincarnations of the prequels.

The difference is that Forever and Ever is a full fleshed drama while Good Bye My Princess: Special is made up of snippets.

Both dramas have an outspoken female lead and have a mixture of comedy, mystery, action and romance

Both have that unique combination of making you feel happy, sad, confused, empty, overwhelmed, and captivated at once.
Both have multiple couples with Goblin having 2 and More Than Blue having 3.
Both depict the power of true love and what people will sacrifice for the person they love the most.
Both have beautiful OST’s
Both involve working in a music setting- (record company for More Than Blue and radio station for Goblin).
Both have great performances
Both will stay in your mind for a long time after you have finished.

Good Korean time travel story. Heartwarming stories. Involve the male lead love of the woman. Past, present and future. Worth watching

Back and forth. Unfinished business.love, family, friendship, heartwarming movie. Past at present. Good movies

The main lead went back and forth. Future self. New discover. Heartwarming movie. Desperate, emotional but beautiful.

Time travel. Mystery. Confuse first but king of clear out. A touch or romance. One is Korean one is Japanese

- Both dramas related to insurance
- Insurance investigations, foul play cases, murder/cold cases to solve
- Fight against corrupt/powerful people who want to cover up their crimes at any cost
- Twist & turns of truths
- Action , Thriller pack scenes

- Both dramas related to insurance
- Insurance investigations, foul play cases, murder/cold cases to solve
- Fight against corrupt/powerful people

Both dramas are time-travel romance drama.
In See You Again, FL dies in a car accident and ML uses a camera to time-travel back in time, hoping to save her.

The two dramas from these two franchises also carry the same theme, namely Knights. And there are also differences, namely: Ryusoulger has a Dinosaur theme and Saber has a Book theme.

Both of these dramas get Anniversary before Fourze and Revice. The content of the story is also the same, but has the theme of Wild animals, God Beasts in one device with the title Story book in the same. also met his ancestors (Kamen Rider #1) for the first time in the history of the Kamen Rider franchise.

Actually, they are the 2nd Super Hero Toei in the Reiwa era, at the same time the timeslot is also the same and at the same time has crossover on the same day and movie.

I'd recommend both for great hate to love sizzling chemistry and clashes you can't look away from. Male falls first in both.