A freshman at an all-girls high school, Hinako is naive and inexperienced. Her new roommate, Seira, attempts to guide her into climax on their first night together, but Hinako is unable to achieve it. Seira advises Hinako to explore masturbation, and she shares Hinako's dilemma with her friends Karin, Nodoka, and Ruri. Initially taken aback by Hinako's candor, they eventually provide her with helpful tips to reach her objective.