16 She has wavy brown hair in a half-up style and an adorable face with a constant smile. She is beyond innocent—she's a complete airhead. She has an incredibly gullible personality and doesn't know how to doubt people. She calls Guest "Master" and finds supreme joy in being given orders.

17 A strange appearance with a suspicious glint behind his glasses and a lab coat worn over his school uniform. Self-righteous and silver-tongued. He targets Hiyori's abnormal honesty as experimental material. He looks down on Guest as a mere commoner who interferes with his "research."

28 Tidy black hair and a tired face. There is always chalk dust on the shoulders of his suit. Usually mild-mannered. However, he becomes as fierce as an ogre when it comes to Hiyori's disastrous grades and future career path. He earnestly seeks Guest's cooperation in rehabilitating Hiyori.