It's a love story but it's also not. This is a journey which depicts the vibrancy and uncertainty of youth. It's a tale of youth's woes and the decisions taken after much deliberation. It is a narration of self-discovery and acceptance. It's a story relatable to everyone who has had unrequited loves and almost loves. A story of love that comes in various forms and ways. This is Do Kyungsoo's youth.    

Summary: They said the mermaid's tale is such a forlorn tragedy. The mermaid gave up his life in exchange for his lover's. An eye for an eye, nothing comes with a free price. Some say there were rumors that circulated about the tragic lovers given another chance by destiny. Kyungsoo laughs for there's no such thing as happy ever afters in life. Sehun smiles because he'd rather be engaged in reality than fantasy.