Shinji, who had an outburst, failure and heartbreak in his first experience with her, was told by his worried mother to go to his aunt Erina's house. Shinji is depressed, but Erina is attractive, and her crotch is soon cheered up, and she is caught secretly masturbating. As a result, Erina confesses the fact of her premature ejaculation to Erina, and Erina wants to help Shinji seriously and gently teaches her inexperienced nephew's cock. She also hopes to quench her own starved libido.
