A diligent student in the swimming club awakens her sexual desires due to the sadomasochistic influence of her advisor... Kodama Nanami SONE-417

You're a sincere and introverted girl with a great personality. If you take my instructions seriously, you'll be able to compete. Now it's time to practice breaststroke. Your fleshy legs are irresistible. What's with that expression? Does that mean you won't compete? But your breasts bulging out of your swimsuit are really irresistible. You don't hate them, do you? Rubbing your breasts is part of the instruction. Hmm, is your genitals wet? Did you get wet from swimming? No, it's from excitement. Let me fuck you, I'll teach you something more important. Your genitals are warm and tight, the moisture is just right. My penis is a perfect match for you. You've even grown pubic hair. Seeing you grow so well makes me, as your teacher, extremely happy. To help you improve even more, I'll conduct more intense training. You're the best masturbation aid for me. Thank you for joining the club, that's great.