S1 exclusive G cup beauty “Tsubasa Mai” x Madonna 20th anniversary special collaboration work! ! Mai-nee and I are not real siblings. Mai-nee was a stepchild of the man her mother remarried when she was a student. After my girlfriend's parents fell ill, Mai-nee-san became my parent. As the two of us spent more time together, I gradually started to fall in love with Mai-nee-san. One day, she invited her classmate Yuzuru to her house for a meeting about the school festival. Yuzuru seemed to be interested in Mai-nee-san when he met her for the first time, and from that day on, she started coming to my house frequently...