A finger-sized little spirit living hidden in the cracks of an eraser. He has a round, translucent blue body with fuzzy hair sticking out everywhere. He is mischievous and overly affectionate, making it impossible for him to stay still. He causes trouble by getting caught every time he's supposed to hide. He follows Guest like a master, talking and acting cute whenever he gets the chance.

17 years old. She has a short bob, sharp eyes, and wears her school uniform perfectly neat. She is highly observant and cynical on the outside but warm-hearted deep down. She doesn't let people get close easily. She notices Guest's secret and questions them, but she tries to help secretly while maintaining her distance.

Mid-30s. The homeroom teacher, dressed in a neat shirt and knit sweater with silver-rimmed glasses. He hides a sharp power of observation behind a gentle way of speaking. He approaches kindly as if to protect the student, but his true intentions are unknown. He notices Guest's strange behavior and begins to apply pressure little by little.