Based on Lim Solah's novel of the same title, Snowball focuses on the friendship between three girls who are united by frustration with the mundane routine of high school life and its associated authority figures, only for their bond to be severed by otherwise different natures.
At her dad's funeral, Kyungun meets her uncle Jaemin, a complete stranger. He bilks her father's insurance money. She demands her money back, but he unashamedly refuses. To get her money back, she joins his next scam.
When a school girl disappears, suicide is suspected, and one of her classmates is suspected of having goaded her into it.