structural:scholar_edition
Japan

Before monogamy was legally imposed in the Meiji period, concubinage was common among the nobility. Its purpose was to ensure male heirs. For example, the son of an Imperial concubine often had a chance of becoming emperor. Yanagihara Naruko, a high-ranking concubine of Emperor Meiji, gave birth to Emperor Taishō, who was later legally adopted by Empress Haruko, Emperor Meiji's formal wife. Even among merchant families, concubinage was occasionally used to ensure heirs. Asako Hirooka, an entrepreneur who was the daughter of a concubine, worked hard to help her husband's family survive after the Meiji Restoration. She lost her fertility giving birth to her only daughter, Kameko; so her husband—with whom she got along well—took Asako's maid-servant as a concubine and fathered three daughters and a son with her. Kameko, as the child of the formal wife, married a noble man and matrilineally carried on the family name.

A samurai could take concubines but their backgrounds were checked by higher-ranked samurai. In many cases, taking a concubine was akin to a marriage. Kidnapping a concubine, although common in fiction, would have been shameful, if not criminal. If the concubine was a commoner, a messenger was sent with betrothal money or a note for exemption of tax to ask for her parents' acceptance. Even though the woman would not be a legal wife, a situation normally considered a demotion, many wealthy merchants believed that being the concubine of a samurai was superior to being the legal wife of a commoner. When a merchant's daughter married a samurai, her family's money erased the samurai's debts, and the samurai's social status improved the standing of the merchant family. If a samurai's commoner concubine gave birth to a son, the son could inherit his father's social status.

Concubines sometimes wielded significant influence. Nene, wife of Toyotomi Hideyoshi, was known to overrule her husband's decisions at times and Yodo-dono, his concubine, became the de facto master of Osaka castle and the Toyotomi clan after Hideyoshi's death.