Koshu benjo (Japanese: 公衆便所, “public toilet”) is a derogatory metaphor that likens to a sanitary facility anyone may use a female figure who permits sex with unspecified many men, and it is one of the terms of verbal humiliation in Japanese-language adult media. Its original meaning is “a toilet as a public facility,” but centred on the adult manga (erotic manga) and adult videos (AV) from the 1990s onward, the usage settled as a rhetoric that degrades a female character to the extreme as a sexual object. It is characterised by functioning not as a form of address for real women but as an insult sign within fiction. It corresponds to the English-language slang cumdump and public-use toilet, and the metaphorical structure that treats the female body as equivalent to “a container for excrement” is observed regardless of East or West.

Overview

The metaphor “public toilet” is a repeated linguistic operation that positions the female body as a receptacle for excrement, compressing into a single word four implications: the unspecified, the indiscriminate, the shared, and the unclean. Concretely, it has the following discursive features: it denies individual relationship and defines the targeted woman as an existence “anyone can use”; it strips from the woman the right to select the user and erases the agency of refusal; it cuts her off from a private, closed sexual relationship and redefines her as a convenience of the community; and it deliberately overlays the act of excretion onto the sexual act, marginalising the female body by way of disgust.

These implications all aim at an effect as verbal humiliation, and they are read as connecting with the manipulation of the notion of “the unclean” that the anthropologist Mary Douglas discussed in Purity and Danger (1966) citation needed. The sociolinguist Sara Ahmed points out that the emotion of disgust has the political function of expelling the other “outside the boundary of the body,” and the rhetoric of this term can be understood as the same kind of boundary-drawing.

Etymology and the formation of usage

“Benjo” existed as an everyday word alongside kawaya and secchin from before the early-modern period, but the three-character compound “koshu benjo” settles in the period of the development of urban sanitary administration from the Meiji era onward. While it was used as a neutral term referring to an excretory facility installed in public space, its sexual diversion as slang already existed in the postwar sex industry. In particular, expressions such as “toilet woman” and “a woman like a public toilet” are scattered in the kasutori magazines of the Fuzoku Soshi line of the 1950s citation needed.

The usage in the contemporary context was established in the process of the refinement of verbal-humiliation depiction in erotic manga from the late 1980s into the early 1990s. Kaoru Nagayama’s Eromanga Studies (2006/2014 enlarged edition) points out that the erotic manga of this period developed a three-stage narrative type of “violation → acceptance of pleasure → collapse of self-definition,” and excretion-type insult terms such as “public toilet” and “human urinal” came to be frequently used as keywords for degrading the female character in this second and third stage. In the AV industry of the same period, the same word appeared in the advertising copy and lines of works depicting group acts by multiple male performers, and the designation “public-toilet works” settled as a subgenre.

Derivative forms and cognate terms

In the erotic-manga and AV context, the following line of cognate insult terms has formed around this word.

• Human urinal (niku benki): an expression overlaying the very noun for the vessel, “toilet bowl,” onto the body. More concrete than “public toilet,” with a higher intensity of stripping away personhood.
• Public human urinal (koshu niku benki): a compound of the above two words. Frequent in erotic manga from the late 1990s onward.
• Toilet woman (benjo onna): a noun-form usage abbreviating “a woman like a toilet.” It retains an archaic resonance that goes back to literary works.
• Semen toilet, semen tank: a metaphor of a pure liquid-storage vessel, with the conception and implantation functions excluded.
• Sex slave, flesh slave: insult terms of the submission type, distinguished from “public toilet” in their strong implication of an ownership relation.

In the English-speaking world, words such as cumdump, fucktoy, community cock socket, and public-use slut correspond, all sharing a metaphor of excretion or disposal. The Japanese “toilet” expression is said to differ slightly in emphasising the character of building and public facility, as against the English dump (a place of dumping).

Literary lineage

The rhetoric of using the metaphor of a sanitary facility for sexual degradation leaves traces in modern Japanese literature too. In the I-novel-style works of Tanizaki Jun’ichiro, the custom essays of Tanaka Komimasa, and the SM novels of Dan Oniroku, depictions likening a female protagonist or victim to a “toilet” or “privy” are scattered, forming one part of the discourse of the objectification of the female body in postwar literature citation needed. In particular, in Dan Oniroku’s Hana to Hebi (1962– ) and the bondage novels in its line, “toilet” is used repeatedly as vocabulary for verbal humiliation in the process of training, and this was inherited by the Roman porno of the late 1970s and the erotic manga from the 1980s onward. Such continuity shows that this word has been inherited not as a standalone slang but as part of the repertoire of insult terms in sexual representation from the modern period onward.

Function as a term of verbal humiliation

In erotic manga and AV, the word “public toilet” is deployed within the work not as a word describing the act itself but as a verbal violence that shakes the self-definition of the character. Nagayama positions verbal humiliation in erotic manga as a “device mediating the collapse of the subject,” and analyses a type in which, each time the insult is repeated, the inner resistance of the targeted character lessens, until finally she reaches the narrative climax by uttering the same word herself (self-labelling).

This usage connects conceptually with diatribe (invective) in classical rhetoric and with abjection in psychoanalysis (Julia Kristeva, Powers of Horror, 1980). The “internalisation of the unclean” that Kristeva discussed runs in parallel with precisely the depiction in which a person likened to a sanitary facility absorbs herself into that self-definition citation needed. In terms of narrative typology, it is also adjacent to the mesu-ochi (becoming-a-female) plot, and the two are often used together within the same work.

Development as a subgenre

From the late 1990s into the 2000s, in commercial erotic manga a body of works was established that placed “becoming a public toilet” at the theme of the narrative, and a subgenre called “toilet works” formed at doujinshi conventions (Comic Market) as well. The features of the narrative type are: an introduction in which the protagonist female character is forced into sexual acts at a school, workplace, or public space; the stepwise progression of pleasure acceptance through repeated depiction; and narrative closure through the dissolution of self-identification and a “toilet declaration” (a scene in which she names herself a “toilet”).

In the AV industry, the same narrative type circulates as title words such as “public toilet,” “public human urinal,” and “gonzo public toilet,” and is combined at high frequency with act types such as double penetration, group acts (fukusu play), and bukkake. It has a high affinity with exhibitionism and public play, and the emphasis on the character of public space is the cross-genre common element.

Comparison with overseas slang: correspondence with cumdump

In English-language pornography, cumdump is slang defining the female body as “a dumping ground for semen,” a word that, in terms of word-history, circulated mainly on internet adult sites from the 2000s onward. The correspondence can be organised as follows.

Japanese	English	core of the metaphor
koshu benjo	public toilet / public-use slut	public facility, shared resource
niku benki	cum receptacle / cum container	vessel, utensil
seieki benjo	cumdump	dumping ground, waste disposal

In the English-speaking world, “dump,” which implies the act of disposal, tends to be used more frequently than the “toilet” as a building, and this is also argued to be a lexical structure reflecting the difference in the history of waste disposal and the concept of public sanitation citation needed.

Criticism from a feminist viewpoint

The “public toilet” expression has been an object of criticism from feminist criticism and gender studies as a typical insulting usage that materialises (objectifies) the female body and equates it with excrement. Naoko Mori’s Pornography: Women in the Discourse of Sexuality (2010) points out that the representation of women in pornography is repeatedly constructed with utensil metaphors such as “vessel,” “hole,” and “processing place,” and analyses the relation in which this reinforces, circularly, the actual vocabulary of misogyny.

Momoko Nakamura’s Words and Violence (2014) argues that an insult is not merely a tool of emotional expression but a linguistic practice that reproduces social-class and gender structures. Excretion-type insults such as “public toilet” are noted as being able to preserve the lexical foundation of actual sexual discrimination, by repeating a grammar that positions women as “the side that is used.”

On the other hand, from the standpoint defending the function of fictional insult terms, there is also an argument that grasps pornography as ritual violence or safe transgression, and the evaluation of this word connects with the contention over freedom of expression and the regulation of expression.

Positioning as expression

“Public toilet,” in contemporary Japanese adult media, can be organised as a word that functions as an insult, working not as the act itself but as a verbal marker of the collapse of the subject; that has a rhetorical inheritance from postwar literature and modern custom-ethnography; that shares a metaphorical structure with the overseas slang cumdump while retaining the implication of “public facility” peculiar to Japanese; and that, while being an object of feminist criticism, is also the subject of advancing analytic research as a sign within fiction. The context of use as an insult against real women and the context of use as a sign composing a narrative type within fiction need to be strictly distinguished, and research on the latter is an important object for clarifying the cultural-historical position of insult terms in pornography.

See also

• Bukkake — an act sign running alongside insult and materialisation
• Fukusu play — the act form that narratively supports “the unspecified many”
• Batou (verbal abuse) — the superordinate concept of verbal humiliation in general
• Chijo — an adjacent type with the direction of agency reversed
• Double penetration
• Dan Oniroku