Both FLs grow up as sweethearts with a man who to protect them wipes their memories and sends them to marry another man, continuing to support them from the background. In PS the FL ultimately falls in love with someone else, in TLLTM she returns to him. Both dramas have palace scheming.

Both FLs lose their memories and start entirely new lives, while the MLs who loved them re-enter their lives and help them.

Both are short length vertical dramas with a censored LGBTQ+ relationship between the leads, one of whom ends up in the opposite gender body and falls in love with the ML.

The movie is a sequel to the drama and continues the story of the leads after they're adults.
........................................................

Both FLs are the older teachers of the MLs who start out rebellious but quickly fall head over heels for the FL and start chasing her.

Both FLs are ML's somewhat older teacher who he falls in love with long before she reciprocates his feelings.

Both FLs are modern day girls with difficult lives who enter a fictional VR historical world where they must accomplish tasks. MLs are also from the real world, something that's not revealed until close to the end of the drama. Both have similar open/implied to be happy endings after ML sacrifices himself in the game to save the world.

Both FLs are modern day girls who enter a VR historical world where they must accomplish tasks, and fall in love with the ML, who is also from the real world, along the way.

Both FLs are modern day people who enter a fictional historical VR world where they have to accomplish tasks. Both worlds involve demon hunting and ML is at least partially a demon.

Both FLs are modern girls who transmigrate into a VR style fictional historical world in which she has to accomplish tasks.

Both have the same director, so the same style and vibes. Both have excellent action scenes and BL undertones.

Both are short LGBTQ+ romances between a human and a ghost. One is BL and the other GL.
.........................................