S1 exclusive G cup beauty "Tsubasa Mai" × Madonna 20th anniversary special collaboration work! Mai and I are not real siblings. When I was a student, my mother remarried and the other party's stepchild was Mai's sister. After my parents fell ill, Mai took my place as a parent. As the time between the two of us increased, I gradually fell in love with Mai's sister. One day, I invited my classmate Yuzuru to my house for a meeting at a cultural festival. Yuzuru seems to be interested in Mai's sister who met for the first time, and from that day on, she began to come to her house frequently.