Marina's sexual desire is so strong that she wants to masturbate anywhere, anytime. In the pool where everyone is, in the gym where the guys are training, in the hallway next to the classroom during class, while her female friends are having sex, in the gym. She knows she shouldn't do it in these places, but... it's precisely because she knows that it feels so good that she can't stop. On top of that, masturbating alone isn't enough for her, and she even has sex with the guys she witnessed on the spot...