Both are mini dramas with a modern day doctor time traveling to the past and curing the ill ML with her skills.

Both are historical mini dramas in which the leads attend school together, falling in love along the way.

Both are Joseon era historical stories. Both MLs are matchmakers and the FLs escape and hide out with them, with the ML intending to help her find her perfect match. But the two end up falling in love.

Both begin with the vampire or vampire-like ML in a coffin and being unexpectently woken up by the human FL. The ML then begins living with the FL and they have a supernatural connection that one can sense the other. Both are a mix of drama and comedy, with an urban setting.

Both are about a vampire who becomes involved with a "special" human.
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Both are about a vampire who becomes involved with a "special" human.
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Both have vampires.
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Both have vampires involved with a special human.
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Both are melancholy historical dramas with a master ML/disciple FL who are not allowed to be together and power struggles within the palace. Both dramas have a sad ending that is "fixed" in some way by a sequel (BCTSAL has a movie and OAO has a sequel series).

Both are mini dramas in which the FLs loses her memory of a night/the past and has raised her young son alone. Unexpectently, she enters into a contract relationship with the ML, later learning he's her son's father.

Both FLs are drugged and have no memory of the night they spent with the ML. They have a son as a result of that night, and search for the father, ending up involved with the ML in the process.

Both are mini dramas with the same ML and FL as the main couple.
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