Idle Mermaid(2014)

Idle Mermaid is a romantic fantasy series about Ha Ni, a mermaid princess who abandons her underwater kingdom after falling for a human man named Hyun Myung. She transforms into a human and moves into his temporary housing facility, where residents prepare for employment. Pragmatic and job-focused, Hyun Myung is unaware of Ha Ni's true identity or her impossible deadline: she has just 100 days to make him fall in love with her, or she'll be forced to return to the sea forever. As Ha Ni navigates human life and pursues his heart, the question becomes whether love can overcome the fundamental differences between their worlds—and whether Hyun Myung can see past his ambitions to notice the woman willing to sacrifice everything for him.