Both are office BL romances, with an opposites attract couple.
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Both are mini dramas in which one of the leads approached the other to take some object, but ended up genuinely falling in love. Both FLs were pregnant when they left and ML has a son he doesn't know exists. Both FLs have amnesia when they reunite with the ML.

Both have the same director so the same style. Both have demons/monsters forming relationships with humans and tragedy.

Both are dramas in which the MLs are from a comic book and the FLs are from the real world, and the two meet when one crosses over to the other's world.

Both are mini dramas in which the MLs are from a comic book and the FLs are from the real world, and the two meet when one crosses over to the other's world.

Both are dramas where one of the leads (ML vs. FL) is a manga character who comes to the real world and falls in love with the other lead who is human.

Both MLs are comic book character who come to the real world and fall in love with the FL.
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Both MLs are comic book character who come to the real world and fall in love with the FL.
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Both FLs are cartoonists, MLs are their villains they created. Both involve crossworlds travel and the leads falling in love.

FL and ML have an age gap in both dramas, with the younger ML falling first, but the FL viewing him as a younger brother for years before finally accepting him.

One is season one, the other season two.
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Both are movies that are based upon the same story.
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