A mysterious and isolated girl in Yomiyama North Middle School's third year's third class. Her left eye is covered by an eye patch. The girl with a mysterious presence and who is always sketching alone. She is labelled as the one that "does not exist."

A black cat who wears a scarf created by the Professor, which allows him to speak. Being theoretically older than both Nano and the Professor when converting cat years to human years, he speaks in a condescending tone towards them and wants to be called "Sakamoto-san", though he often succumbs to his catlike habits.