Hari Koo (구하리, Gu Hali) is one of the main protagonists of the overall series, and is the older sister of Doo-ri Koo. Hari is a beautiful girl with hazel coloured eyes and fair skin. Her brown hair is pulled into a ponytail on the side of her head with a pink hair tie. Hari is kind, nice (sometimes/depending on the situation), and she cares and protects people she doesn't even know. Though she can be kind she is also extremely protective of her younger brother, Doori.