In both the FL dies and ends up in another girl's body.
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Both dramas have the FL in another girl's body and a royal ML who is initially cold towards but quickly entranced by the FL. Both MLs have an evil brother who desires the FL.

In both the FL's spirit is in another girl's body following death and there is a love triangle involving the FL, the ML, and the SML.

Both dramas have the FL occupying another girl's body, and a royal ML with a stoic personality.
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Both FLs end up in another girl's body and fall in love with the ML with whom either they or the original girl had a past romance with.

Both are mystery/romance dramas with a historical setting, featuring a band of characters working together to investigate and solve cases.

Both have the main characters investigating episodic mysteries, with a slow burn light romance between the ML and FL.

Both have a trio investigating episodic mysteries, with a slow burn light romance between the ML and FL.

Both couples work together to investigate cases. Both dramas start out more heavily focused on the mystery genre, with a slow burn romance mostly toward the second half.

Both couples work together to investigate cases. Both dramas start out more heavily focused on the mystery genre, with a slow burn romance mostly toward the second half.

Both are dramas focusing on a couple investigating cases together, with a mostly light tone and a slow burn romance.

Both are dramas focusing on a couple investigating cases together, with a mostly light tone and a slow burn romance.