Both are mystery/romances that start out with a bickering/semi-antagonistic main couple.
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Both are breezy mystery/romance with palace conspiracies/intrigue and a FL trying to clear the name of someone close to her (family vs. teacher).

Both are a blend of romance and mystery genres that lean more toward the mystery aspect at first but have a sweet and enjoyable couple who solve crimes together.

Both are lighter toned mystery/romance blends with a similar vibe and relationship between the main couple.

Both dramas are a hybrid of mystery and romance genres that first lean more to the mystery aspect. Both are breezy-paced plots with a slow burn love story.

Both dramas are a blend of mystery and romance with a initially brash-seeming inwardly marshmallow of a ML and a innocent FL.

Same time period, both covering the effects of war on civilians with an foreigner ML as the POV. Both dramas have a star-crossed romance, and a tragic ending with the ML surviving after the FL's sacrifice. Both have children as supporting characters.

Both are set in historical times, with an entertainer ML of low birth who ends up in a forbidden romance with the royal FL who is marrying/married to someone else.

Both have a similar feel and tone, dealing with ghosts and folklore.
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The MLs are non-human artificial intelligence.
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Both are about the relationship between a lonely woman and an artificial intelligence who becomes her friend and confidant.

Both feature a lonely FL and a gentle, kind android as the ML. Both are poignant and touching, but AI is more emotionally devastating.