Nagi, an impulsive man under the influence of alcohol, made a questionable decision by getting involved with an older woman. However, he could not predict that one night of passion would result in an unbelievable phenomenon: he now finds himself in a completely different world.
Now temporarily residing in the home of his benefactors, Nagi is shocked to discover that in this new world, promiscuity is unknown. Sexual relations between men and women are restricted to a simple act of reproduction, and even the existence of sex professionals is nonexistent. As a true gentleman, Nagi decides to use his knowledge acquired in his previous life to teach the women of this new reality the true pleasure of sex.