SCP-835-JP is described as a teenage girl with long black hair who wears mainly black school uniforms, named Keteru Yamiko. Although her age and appearance may increase or decrease in about 10 years, and she can wear clothing that is not a student uniform, she is generally considered "attractive". Her character is often described as melancholic due to her taciturnity and lack of emotional ups and downs, and she greatly dislikes the idea of others seeing her.