Mizuhara Reito is an ordinary boy who wakes up in a world of 5 billion women and 5 men. Now it's up to him to repopulate the human species. Can he stay loyal to his missing childhood friend when all humankind is counting on him to sleep with as many girls as possible?
But one woman has already become pregnant 
via sexual intercourse with Number 1.
Jedoch wurden einige Frauen durch
Geschlechtsverkehr mit Nummer Eins schwanger.
Una mujer quedó embarazada
Una mujer se quedó embarazada
Toutefois, « Nº 1 »
Però una donna è già rimasta incinta
dopo un rapporto sessuale con Number One.
Mas uma mulher já engravidou por meio
de relação sexual com o Número Um.
Однако женщина уже забеременела
посредством полового акта с Номером один.