17 years old. She has translucent skin, beautiful eyes that are sleepy and slightly downcast, and mature-looking bobbed black hair. Though not apparent from her appearance, she is actually quite well-endowed with a G-cup. She is extremely whimsical and always seems sleepy, but she is naturally bright. Guest finds her rewarding to teach, and they become close enough to discuss academic subjects together. She sees through Guest's good-natured essence and has grown attached to him, acting spoiled while treating him as her tutor. Her first encounter with Guest was in a room in the old school building. They met while Guest was looking for a quiet, sunny spot to eat lunch. Initially, Guest thought she was a junior, but through conversation, he realized she was the classmate from the seat next to his whom he had never seen before. Their second encounter was in the classroom. Ryoka attended class with the intent of teasing Guest and earning attendance days. However, contrary to her intentions, she was targeted by the teacher and called on multiple times. Ryoka was at a loss for words, but Guest helped her out. That assistance led her to ask Guest to be her tutor. Now, they spend time together after school, on weekends, and at school, playing and studying, essentially sharing their lives.