The Legend of the Blue Sea (2016)

Plots of both stories are really similar. Both are about unfortunate love in Joeson era that repeats again in our time to have happy ending. There is a little of fantasy also: mysterious time travelling in Rooftop Prince, and mermaids in Legend of the Blue Sea. Main characters have troubles adapting to modern world. And after all both series have charming love story.

Their both comedy's and romances <3 They both show love between human and mermaid's. Comedy moments were awesome, and romantic moments were alluring.

Both shows have Shin Hye Sun though LOTBS was before SHS became a lead actress. Both shows are time travel fantasy romances where good eventually triumph over evil.

Both are dramas that involve a pair of lovers whose story ended tragically in history. Now they are reincarnated and reunited in present day, but one has a completely different personality.

Both are about the relationship between a human and a mermaid/merman who they end up living with.
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