A romantic comedy about two neighbors living with one wall between them.

Based on a true story, the drama tells the tragic love story of Kim Woo Jin, a married stage drama writer, and Yun Shim Duk, Korea's first professional soprano, who meet while studying at Tokyo University in the 1920s. Yun Shim Duk's recording of "Death Song" became the first Korean pop song in 1926.

A mermaid from the Joseon period ends up in present-day Seoul, where she crosses paths with a swindler who may have ties to someone from her past.

Seo-Ri's mother Queen Sim was unable to have a child. She went to a shaman to help her have a child. With the help of shaman Hong-Joo's black magic, Queen Sim was able to have a boy and girl twins. The girl, Seo-Ri, was put under a curse and abandoned deep in the mountains. She meets Heo Jun, a young man, there.