Ruri Nonomiya resides in the same dormitory as protagonist Takuro Hayami. She is inseparable from Yuki Miyagishi, her constant companion defining her place within the group. As the youngest and most energetic core dorm resident, her girlish pigtails reinforce her lively, youthful image.

She takes opportunistic sexual advantage of Takuro, aligning with a recurring pattern of female behavior towards him. Her participation extends to group endeavors, notably the Baseball Club initiated by Saori Otokawa. The documented materials provide no significant individual story arcs, background history, personal development, family details, past experiences, motivations, or evolution beyond her established interactions and role.