Sexuality in Japan developed separately from that of mainland Asia , as Japan did not adopt the Confucian view of marriage , in which chastity is highly valued. Monogamy in marriage is less important in Japan, and married men often seek pleasure from courtesans. Prostitution in Japan has a long history, and became especially popular during the Japanese economic miracle , as evening entertainments were tax-deductible. Decreased sex drive in the 21st century has been blamed for the low Japanese birth rate and declining growth of the Japanese population. Historically, pornography in Japan may have begun as early as the Edo period [ citation needed ] as erotic artwork referred to as shunga that was typically done on woodblock prints. Between the s and '30s in Japan there was a literary and artistic movement known as ero guro which focused on eroticism, sexual corruption and decadence.