Atsushi, Marina's homeroom teacher and boyfriend, was once in a relationship with Marina's older sister, Emi. One day, Atsushi is surprised to find out that the two are sisters. The sisters also find out and become rivals in love, clashing fiercely over Atsushi. Naturally, they fight over his dick! Quadruple breasts give him a titjob in every direction! Fingering and thrusting into the two beautiful big asses! They share the same genes, but they also do missionary and cowgirl positions...