Both are mini dramas in which the FL exchanges places with her identical sister, leading to her becoming involved with the rich ML.

Both are about the FL swapping places with her identical twin sisters, leading to her becoming involved with the ML.

Both are mini dramas with the same actor and actress as the ML and FL.
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Both are mini dramas with the same actor and actress as the ML and FL.
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Both are mini dramas with the same actor and actress as the ML and FL.
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Both are mini dramas with the same actor and actress as the ML and FL.
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Both are mini dramas with the same actor and actress as the ML and FL.
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Both have firefighters and a ML who often breaks the rules for the greater good. Both FLs are adopted.

Both are historical mini dramas about a body swap between the ML and the FL.
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Both are historical mini dramas about a body swap between the ML and the FL.
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Both are mini dramas about a body swap between the ML and the FL.
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Both dramas are about a body swap between the ML and the FL. Both have a historical to modern day time travel element.