Mio returns to her parents' home on the day of the fireworks festival. Her sister's sons have grown up and become men. When she sees her nephew's rock hard cock, Mio's body suddenly starts to ache! First, she shows her nephew how to masturbate, making him fully erect, then she makes him squirt with a handjob, making him shoot a semen beam, and then she squeezes his cock with her vagina! Her younger brother, who was watching from the closet, approaches Mio in the shower, saying, "I want to have a chance too!", and gets his semen milked by her big tits! And so begins a jealous battle between the older brother and his younger brother, Mio, over who can insert his penis into her and who can't. Mio steps in to mediate, saying, "Don't fight about me!" What will happen!?