Both FLs disguise as a boy to enter a place that only admits men. Both MLs have a hidden identity as well.

Both are Republican Era mini dramas in which the FL wrongfully blames her former fiancée for murdering her family and returns under a new identity to take revenge.

Both are xianxias in which the FL has a hidden powerful identity even she is initially unaware of which puts her at odds with the ML. Both are bittersweet stories.

Both are dystopian settings with unique worldbuilding.
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Both are historical drama specials, one of which tells the story of Prince Sado and the other of which tells the story of his son Prince Yi San dealing with the aftermath of his father's legacy.

Both are Republican Era dramas with a love/hate relationship between the leads in which the ML falls first but the FL is troubled by his actions and takes a long time to reciprocate. Both SMLs are initially closer to the FL and spiral downwards over the course of the drama. Both couples marry, have a turbulent relationship, lose and unborn child, and then separate for a while. Both MLs are presumed dead in the final episode, only for the FL to spot their picture and go to find them.

Both are fun reality shows based upon fantasy dramas with Ding Yu Xi.
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Both are mini dramas in which the ML poses as his identical twin, as the FL who he was in love with tries to figure out his identity and secrets.

Both MLs fall in love first and pursue the FL but she doesn't like their behavior/mistrusts them and takes a long time to reciprocate his love. Both MLs are generals, SMLs hopelessly in love with the FL. Both couples marry, and the FL becomes pregnant and miscarries, followed by a several years separation in which one of the leads believes the other is dead. Upon their reunion, FL has a new identity and is now on a mission.

Both are historical mini dramas in which the FL is raised as a boy in order for her to become the city lord. The ML or other FL has a past connection with them and learns their secret.

Both FLs had a past connection to the ML when he was a child, she then dies and is reborn. Years later the FLs reunite with the ML who is now an adult and have never forgotten her, as well as the family they left behind in their past life.

Both are mini dramas in which the ML approaches the FL under false pretenses but genuinely falls in love. Both couples are younger ML/older FL, both FLs are business women who the ML work for/with, and both FLs had a former fiancée/boyfriend who died or disappeared.