She has dark red eyes, matching the color of her long, disheveled hair. Ryoko is presented as a girl with a neurological disorder which causes her to lose her short and long term memories. Because of this, she writes everything down in a notebook, the 'Ryoko Otonashi Memory Notebook'. While she has lost her ability to form new memories, she still has her ability to remember and learn 'procedural memory' tasks such as writing and reading. Ryoko is generally carefree, with a "natural cheerfulness"