Rui is the teenage daughter of Kazuichi Souda and Ryota Mitarai. Hot-headed and impulsive, she also tends to swear on a regular basis and makes it known when she dislikes something. She identifies mainly as genderfluid, usually using she/her pronouns. She has a tendency to get flustered in front of girls and also knows more about robots than anything else. She has a hard time connecting to human emotions.