Kei is a supporting character in the anime film Cencoroll. She is a female teenager with black eyes and black, shoulder-length hair. Her role in the story is primarily defined by her relationship with the main character, Yuki, whom she accompanies on the bus to school each day. Kei is portrayed as a dependable and reliable person who serves as a friend to Yuki.

Kei does not possess any notable abilities, nor does she undergo significant development within the narrative. Her background and personal motivations are not explored. Within the story, her function is to be a supportive presence for Yuki as the central events involving the mysterious creatures unfold, but she does not play a direct or active role in the main conflict. No information is available regarding her specific background, motivations, or any other significant relationships.