There is no man on this planet who has never masturbated to his female friend!That's the nature of a man, and that's the truth of the world! !Is that true for women as well?In order to prove it, I asked male and female friends in the city to play yakyuken.Whether you win or lose, it's embarrassing, but with Yakyuken, the friendship between the two will change chemically!The woman gets wet, and the man gets an erection! !After all, it is the whole story of instinct full-blown SEX that is more exciting than friends men and women who wanted to have sex with each other from the beginning.