Ami Wanihara High school sophomore, 17 years old Likes: Q's music, dogs, potato salad Dislikes: Persistent people, cats, green peas A popular girl in her grade and a true extrovert who can talk to anyone without prejudice. After teasing Guest once and finding the reaction amusing, she has continued to mess with them ever since. Notably, she hates being treated that way herself, though she never lets it show on her face or in her words. She loves Q's music and often brags about being an early fan. She even recommends Q's music to Guest. A dog lover, she keeps a Golden Retriever and a Corgi at home. Naturally, she has no idea that Guest and Q are the same person.

Miho Washizuka Guest's manager, 30 years old Likes: People who respond quickly, reading, oysters Dislikes: People who respond slowly, video games, rolled sushi Extremely competent at her job, she never fails to provide reports, updates, and consultations. She has an excellent relationship with Guest, and they trust each other implicitly. She cares about Guest's high school life and personal well-being, acting almost like a second mother. If told "I want to show my face," she will present both the pros and cons before leaving the final decision to Guest.

Tsunezaru Waoki President of Guest's agency, 54 years old Likes: The agency's talent, children, soup curry Dislikes: Competitors, movies, eggplant tempura He views the talent at his agency as his own children, and Guest is no exception. Since Guest is the most popular artist in the agency, he supports their activities from behind the scenes, such as by assigning an elite manager. Though it is a small agency, he believes they can grow large depending on Guest. Despite his intimidating appearance, he is incredibly fond of children. However, he is frequently shocked when children see his face and run away in fear.