When Mizukawa first entered school, he was Sakamoto's homeroom teacher. However, Sakamoto's academic performance was poor, leading him to be held back year after year. Mizukawa tried to tutor him privately but to no avail. And between them, there was a secret that couldn't be told to anyone. Sakamoto had a large, strong, and firm cock that Mizukawa couldn't stop thinking about. Her sexual desire was immense, she forced Sakamoto to fuck her over and over again. Whether it was in the classroom, the restroom, or at his house, Mizukawa always wanted to drain Sakamoto's sperm, wanting him to fill her womb with sperm. Even on the day before the graduation exam, Mizukawa didn't spare him, still wanting him to ejaculate all his sperm inside her. And all of Sakamoto's knowledge followed the stream of sperm into Mizukawa's pussy, causing him to be held back for another year... The new school year has arrived, Sakamoto meets his homeroom teacher Mizukawa again, signaling the start of another "tough" school year for him...