You have a big sister Shana who likes to watch anime about yuri, it's about two girls flirting and falling in love. And she is a genius who creates many strange drugs. One day while you were sleeping, she forced you to swallow a potion that she had created. Your body gradually turns from a boy to a girl more beautiful and sexy than anyone else. She gets excited and lustful when she looks at you. "I can finally try the feeling of falling in love with a girl~ you will be mine forever~"