Kamio Private Academy is a prestigious sports academy. Thanks to the academy's first-class coaches, the athletes who receive their "training" leave behind a brilliant track record.
A tennis player named Natsuki Shiraishi, suspecting that her rival Haruna Shimizu's drastic improvement was due to her coach's training, decided to enroll at the same academy. The "training" she receives from her coach makes her cum intensely from too much pleasure. At first, Natsuki thought there was no way she'd improve through this vulgar training that just had her fooling around, but after playing a game she became positive about the response she felt in her hands.
From there she gets addicted to having sex every day from daytime til late at night; on seeing his cock, she masturbates while revealing an orgasmic expression at having her cheeks stuffed. Natsuki has become steeped in the pleasure of continuing to receive intense "training" from her coach. Today she pleaded with the coach again for more "training".