Tomoki, a timid salaryman lacking confidence, finds himself in an unexpected situation after a night of heavy drinking following an office party. Awakening to a kiss from Haru, a call boy who mistakenly landed at Tomoki's doorstep, he is offered a unique proposition. As an apology for the mix-up, Haru becomes Tomoki's mentor in matters of intimacy, drawing from his expertise as a professional in the field. Grappling with his insecurities around sex, Tomoki accepts Haru's guidance, leading to a transformative journey of self-discovery and empowerment.