「Female crotch」as SEX SLAVE. Any LOW-CLASS, oppressed person, female or male (crotches from both sexes can and are used in a similar manner). Pressed bean curds as cold TŌFU that is squeezed, oppressed for a long time, as is a SLAVE, but more likely is a reference to female genitalia often being covered with a variety of curdled and clotted seminal fluids…tōfu is made from curdled 'bean milk' (soy). Tōfu uses glyphs meaning「meat warehouse, rotting (腐), clitoris bean (豆)」and refers overtly to stinking female genitalia full of coagulation.
「Viewing women as commodities [see 品] was also made customary from Song Dynasty (960 - 1279) forward, both in the suddenly expanded labor market and within relationships. Men could sell their female kin to slavery or prostitution, and frequently did.」
[ https://www.zum.de/whkmla/sp/0910/hersheys/hersheys5.html 2011-04-05 ]
Note that if tōfu smells or tastes sour, it really has spoiled.
Guy, slave, manservant, fellow, samurai page meanings are derived from the fact that samurai used their page boys in the same manner as they might have used a female crotch:「From religious circles [i.e., Buddhists], same-sex love spread to the warrior (samurai) class, where it was customary for a boy in the wakashū age category to undergo training in the martial arts by apprenticing to a more experienced adult man. The man was permitted, if the boy agreed, to take the boy as his lover until he came of age. This relationship, often formalized in a 'brotherhood contract,' was expected to be exclusive, with both partners swearing to take no other (male) lovers. This practice, along with clerical pederasty [i.e., Buddhists], developed into the codified system of age-structured homosexuality….」
[ https://en.wikipedia.org/wiki/Homosexuality_in_Japan 2012-07-02 ]
「In the past few years, police in the United States say they have noticed that traffickers are making their mark on the girls like never before. It's all part of the gang culture that has taken over the sex trade in the streets of America. In a disgusting display of dehumanization, the traffickers brand or tattoo the girls to show they own them. The marks on the girls tell their story on the street.」
「Some girls have several different tattoos. Each time they are worked by a different trafficker, they are branded with different labels. Sometimes it's an old-fashioned money-bags image. Sometimes it's diamonds. Sometimes it's a trafficker's name across the forehead. Sometimes it's an ATM etched on the skin near their groin. We've even seen a barcode put on a girl's wrist, like an item in a grocery store.」
「America has seen these marks before. Slave masters used branding as a way to mark the African American men, women, and children they bought and sold. It's 2015, and slavery is still alive. It's just taken a different form.」
[ https://edition.cnn.com/2015/09/09/us/freedom-project-branding/index.html 2023-05-19 ]

External source definitions …excluding politically incorrect concepts and other meanings deemed offensive today; may include extended definitions, euphemisms, and mnemonics)
Chinese: slave
Japanese EDRDG: guy, slave, manservant, fellow
Unihan extended: slave, servant

Used within names (nanori)
ぬ