In the not-too-distant future, the male birthrate declined so much that humanity was on the brink of extinction. A new law was urgently issued that referred to a "license for free sex. The holder of this license could have sex with absolutely any girl he liked, whenever and wherever he liked. Moreover, according to the new law, a woman had no right to refuse the bearer of this paper. One night Takumi got his hands on such a license. Needless to say, his life changed abruptly?