Eun-Ho (Kim Hye-Yoon) is a gumiho, known in folklore as a mythical creature with 9 tails. She is different from other gumihos. She doesn't want to become a human unlike other gumbos. She enjoys her eternal youth that never changes. She picks out the fun parts in the human world and enjoys them herself. To avoid becoming a human, she refrains from small virtues and accumulating small bad deeds. One day, an unexpected incident takes place.

Kang Si-Yeol (Lomon) is a world-class soccer player. He is the top striker for a famous soccer club overseas. As a soccer player, he accomplished many firsts and he shines brighter than the club itself. He is also the king of narcissism. His life is perfect, but, one day, Eun-Ho appears in front him. His life suddenly changes.