Idol Harem アイドルハーレム

I'm Yura. I have a twin older sister. She is a famous gravure idol, but she always teases me. One day, she suddenly calls and tells me to come to an island where she now stays for her next photobook. When I arrive there, there is nothing wrong with her except for being suntanned. According to her, she called me to replace her since she's got suntanned too much. "We are twins. There will be no problem." "Well, I can't.... Oh, please stop...!" Like this, I've now become a gravure idol though I'm a man....