After losing her mother in an accident, 9-year-old Eun-ha learns to dance and grows as she discovers ways to express herself.

After an accident while traveling with her mother, Eun-ha survives alone in a car that falls into a reservoir. With the after-effects of the accident, Eun-ha is left in the care of her aunt, Ja-young, and in the new environment and people, Eun-ha closes herself off. When Eun-ha enrolls in a dance school with her cousin Bo-ra, she begins to confront her feelings, expressing her anxiety and fear through dance. Meanwhile, Ja-young learns that her sister's accident resulted in suicide and keeps it a secret from Eun-ha. Eun-ha begins to gain attention at the dance school, and Bo-ra, jealous, presents Eun-ha's "fish dance" as if it were her own creation. As misunderstandings and conflicts with her own family build up, Eun-ha struggles with what it means to communicate truthfully and learns how to express herself.

Fish Dance is a story that delves deeply into the complexities of family relationships, the language of pain, and the resilience of the human spirit. It shows how a troubled girl finds a way to become part of a family through dance and connection, and how, despite conflict and obstacles, she finds healing in unexpected places.