Mio goes to a certain swimming class. Her parents both work, so she is always alone. Mio is an innocent girl who doesn't know how to swim or know anything about sex. There are a teacher and adult men in the pool today as well. As she floated around, a group of adult men surrounded her. Let Mio touch the penis that is used to urinate, let Mio lick it, and finally Mio's cock.