W (2016)

Both have a male and a female lead, which future and past can get re-written. They fight against an invisible opponent, who tries to harm the male lead and do their best to stay at the right time and place and possibly together.

Both dramas have characters from fictional work cross over to the real world to harass the authors into changing their stories.

Two young people meet in a fantasy world in which different rules apply. They often switch from this world to their actual reality. Sometimes that creates problems with their surroundings and puts their family and friends in trouble.

W- two worlds this series also have a parallel world. Though there's an anime artist who's writing everyone's fate. Both are thrilling dramas. Lots of intense but Alice in Borderland still doesn't have any romance but in W it has. Lee Jong Suk is the ML.

In W the male lead is from an other World, and in Hit The Top he is coming from the past.
Though that was just the only similarity. They give absolutely different feels.

Both dramas involve one or more of the main characters from a manga/webtoon world that teleports to the real-life world. These manga/webtoon characters get into a romantic relationship with the real-life character.

Both dramas are about a ML who comes from another world (the past/a manga) to the modern world. In both the FL can influence/change events by writing or drawing them in a book/manga. Both couples have a list of romantic things the FL wants them to do. Both MLs begin to fade away, starting with their hands going transparent/able to pass through things. There is also a villain from the ML's world who ends up in the real/present world.

Both male leads are intelligent, capable, and have a tragic, mysterious past haunting them. They are devoted to unraveling this mystery. Both have been wronged by the female lead's male guardian and have similar confrontation scenes with him. Both female leads are warm and make the male lead believe there can be something good in his life. (Spoiler: W has a happy ending; The Smile Has Left Your Eyes does not.)

I felt Love Crossed had the vibe of W.
What happens in "W" is a girl gets into a comic world. She doesn't believe her eyes after getting a glimpse of the boy live. Similarly what happens in "Love crossed" a girl uses a game where she gets a virtual boyfriend and one day she somehow ends up entering a secret house where she finds the boy (her virtual bf look alike) who actually exists in real life.

In both, the ML is a manga character who enters the real world and the FL is a human from our world who has loved/been interested in the character since childhood.

similar story, W is korean drama, Game Breaker (Dream breaker) is Chinese remake Movie.
in both Male Leads are super hot, tall, handsome guys ))

"W " shows connection between cartoon world and real world
"Signal" shows connection between past and present world
both drama story is stop the crime or search for culprit

Both take place in different "worlds" - W has the real and the comic book world, and Will You Be There has the past and the future world.

Both are fantasy shows about romances between two people from different worlds who should have never met if not for a temporal shift in time and worlds. Both are fish out of water stories. Both sets of main characters have to figure out who is trying to kill them and how to survive all the attempts on their lives.

Both has unexplained phenom. Great couple chemistry. Very interesting story line.