We approached a close brother and sister on the street and invited them to a special studio under the pretext of a questionnaire survey! We asked them to take on the challenge of “taking an aphrodisiac once an hour and having sex or you’ll win a prize of 1 million yen!” Before the challenge, both the sister and the brother boasted, “There’s no way I’m going to have sex!” But as the sister took the aphrodisiac, her crotch gradually became hotter and she transformed into a lewd female who saw her brother as a male! The brother and sister could no longer stop themselves, and even though they knew it was wrong, they engaged in incestuous sex without telling the family! The sister became too sensitive from the aphrodisiac and arched her back and came repeatedly on her brother’s dick! They crossed the boundaries between brother and sister and had sex on drugs and creampied each other!