A hidden camera records interviews and hands-on sex training at a brothel that openly encourages full service. Four adult beginners take the test: Risarisa, a 20-year-old F-cup university student; Ai, a 21-year-old university student; Rin, a 23-year-old F-cup dental assistant; and Miku, a 22-year-old I-cup hairdresser and hostess. Their sexual histories, preferences, masturbation habits, and sensitive spots are laid bare before each interview moves into practical intercourse training.