HUNTC-601 My serious, sports-loving little sister retired from her club and her libido exploded! She’s using *me* for "cock-training" instead of sports! After retiring from the team she poured her heart into, she’s got a surplus of stamina and sexual desire—relieving stress by masturbating constantly! But since masturbation alone isn't enough to satisfy her, she unleashes that pent-up lust on me, driving me to the brink of climax over and over again!

My little sister used to live and breathe her club activities, with practice sessions every morning and after school. But now, the serious athlete has retired. While she used to blow off steam through sports, she started spending all her time cooped up in her room after quitting. When I peeked inside, I found her masturbating furiously and climaxing over and over! It seemed her pent-up physical energy had nowhere to go and had transformed into an uncontrollable sexual frenzy. She caught me spying on her; I apologized in a panic, but her reaction was unexpected—she unleashed that unquenchable sexual desire right onto me! I found myself drenched in sweat, pushed to the limit as she repeatedly drove me to orgasm with her boundless energy and lust. She completely wore out my cock—even though I’m terrible at sports and have below-average stamina... Please, give me a break!