Recommendations

1 . In both of them main leads are broken and pitiful and when they met each other , they start to heal themselves and understand that they are not the only one who is tried of living in this world
2 . there is no romance between main leads in both of them
3 . female leads is an outcast in both of them

The story about secretly liking someone for a long time and taking care of them is similar in both movies.
The overall feel and setting is the same. School/University.

I watched train first and then the ghost detective. I am surprised that no one thought the two were similar!
1- the lovestory itself. We know the leads love each other but the show does not make them state the obvious. As in they never declare their feelings to one another but we viewers know how much they love each other. In this way the romance is subtle and beautiful. It touches you deeply especially when you see how far the leads are willing to go for each other.
2- in both shows the leads overcome the impossible to be with one another. In train the ML finds the FL in another universe after her death and in the ghost detective the ML comes back as a ghost to the FL (none of these are spoilers)
3- the antagonists were similar too. Their origin stories, their descent to darkness was kinda similar to me and how it all came down to this question they kept asking

If you enjoyed one you will certainly enjoy the other. I know i did

Both drama has
- Older Woman/Younger man
- Office setup
- Boss/employee, superior/subordinate relationship

Older woman/Younger man relation with office(superior/subordinate or boss/employee) setup. Takane no Hana-san is light-hearted though.

Both about high school girls that are abused at home and bullied at school, founding happiness with a mister (older guy) that helps then run away of their miserable lifes.

Both drama has an older woman at the mercy of a high school student. The younger man ends up falling for the older woman after she helps him overcome his internal conflicts. However, the woman is pining his male relative who is her first love.

Both c-dramas are done by the same director and also written by the same screenwriter. Both are making one stay glued to the screen, wondering about the truth behind what has happened. Both are absolutely gripping thrillers that are unique and very well done

Ancient Love Poetry follows Shang Gu, once a leader of the four immortals, who falls into a deep sleep after sacrificing herself in a trial that lasted 60,000 years. Shang Gu wakes up many years later, and memories of what happened 300 years ago were completely wiped. But her former lover, Bai Jue, never forgot about her. Sacrificing his reincarnation for her life, he waited for her for 60,000 years. Even when his soul disappears, Shang Gu will wait for him forever.

Ancient Love Poetry follows Shang Gu, once a leader of the four immortals, who falls into a deep sleep after sacrificing herself in a trial that lasted 60,000 years. Shang Gu wakes up many years later, and memories of what happened 300 years ago were completely wiped. But her former lover, Bai Jue, never forgot about her. Sacrificing his reincarnation for her life, he waited for her for 60,000 years. Even when his soul disappears, Shang Gu will wait for him forever.

'Light on Me' is a Korean bl drama which follows a love polygon wherein its unclear as to who will end up with who and the storywriters have successfully accomplished the task of keeping the viewers on their tiptoes.

Dear Uranus is a Taiwanese gl drama with a 'choose your ending' sort of ending, wherein a choice is provided to its users.

I find the concept a bit similar in both these lgbt+ dramas.

Both of the movies are showcased in the backdrop of 1970 South Korea and focuses on the darker side of society.

Both main leads met online
Both ML go to university
Both ML are considered popular in university
Both dramas have a love triangle
Both have supporting parents

Both dramas include the career singing
ML struggles in his singing career like FL from LC
Both dramas include a love triangle
Both ML confess first

Both dramas include gaming
Both main leads are pursuing their dreams while falling in love
Both ML and FL have good chemistry
Both FL are known well online/internet ( In GYH FL is a online streamer)(In LC FL is a singer)