Gengoroh Tagame (田亀 源五郎, Tagame Gengorō; born February 3, 1964) is a pseudonymous Japanese manga artist. He is regarded as the most prolific and influential creator in the gay manga genre. Tagame began contributing manga and prose fiction to Japanese gay men's magazines in the 1980s, after making his debut as a manga artist in the yaoi (male-male romance) manga magazine June while in high school. As a student he studied graphic design at Tama Art University, and worked as a commercial graphic designer and art director to support his career as a manga artist. His manga series The Toyed Man (嬲り者, Naburi-Mono), originally serialized in the gay men's magazine Badi from 1992 to 1993, enjoyed breakout success after it was published as a book in 1994. After co-founding the gay men's magazine G-men in 1995, Tagame began working as a gay manga artist full-time.

For much of his career Tagame exclusively created erotic and pornographic manga, works that are distinguished by their graphic depictions of sadomasochism, sexual violence, and hypermasculinity. Beginning in the 2010s, Tagame gained mainstream recognition after he began to concurrently produce non-pornographic manga depicting LGBT themes and subject material; his 2014 manga series My Brother's Husband, his first series aimed at a general audience, received widespread critical acclaim and was awarded a Japan Media Arts Festival Prize, a Japan Cartoonists Association Award, and an Eisner Award. Tagame is further noted for his contributions as an art historian, through his multi-volume art anthology series Gay Erotic Art in Japan.

Tagame was born in Kamakura on February 3, 1964, into a family distantly descended from samurai. The younger of two brothers, Tagame was forbidden from reading manga as a child with the exception of the works of Osamu Tezuka, which his parents believed had literary merit. He became exposed to a broader array of manga by reading shōnen (boys' comics) stories in barber shop waiting rooms, notably the works of horror authors Kazuo Umezu and Go Nagai, whose manga often featured violent and sexual themes. He began drawing as a child, and by middle school was drawing amateur comics for his classmates and teachers. In his early teens he began drawing pornographic manga after reading novels by the Marquis de Sade and discovering the magazine Renaissance, which re-printed material from underground BDSM manga zines; Tagame has remarked that he discovered his interest in BDSM before he realized he was gay.

He became aware of his homosexuality after watching films featuring "naked and bound men" (such as the Italian Hercules series and Charlton Heston in Planet of the Apes) and discovering the gay men's magazine Sabu [ja]. He found that he was uninterested in stories in Sabu focused on romance, and drawn to stories that focused on sadomasochism. In high school Tagame began writing manga professionally, and contributed to the manga magazine June in 1982 under a pen name. June was a yaoi (male-male romance manga, also known as boys' love or BL) magazine that targeted a primarily female readership, and was noted for its avant-garde stories with complex plots and social realism; Tagame's first story in June focused on a "pretty boy who cross dresses" whose father is murdered by his boyfriend. Tagame struggled with his sexuality and interest in sadomasochism through high school, and did not come out until his freshman year of college. He came out to his parents later when, during a trip abroad, he sent them an email using his pseudonym, and upon returning to Japan his father searched for said pseudonym and found his biography on Wikipedia, where he was described as a gay erotic artist.

Upon graduating high school Tagame moved to Tokyo to study graphic design at Tama Art University against the wishes of his parents, who expected him to attend the University of Tokyo and become a banker. Throughout college he submitted gay erotic stories, illustrations, and manga to Barazoku, René, and other gay and BL magazines under a variety of pseudonyms. He eventually settled on the pen name "Gengoroh Tagame"; both words are Japanese terms for different species of water bugs, which Tagame chose to differentiate himself from the "macho or romantic" pen names used by other gay Japanese artists. While on a student art tour of Europe, Tagame discovered the American leather magazine Drummer at a bookshop in London. The magazine featured homoerotic and fetishistic illustrations by western artists such as Tom of Finland, Rex, and Bill Ward, and would heavily influence Tagame's art. After graduating university he began to work as a commercial graphic designer and later art director, while continuing to write manga and prose fiction.

The 1980s saw an increase in the popularity of gay media in Japan, a trend inspired by the cultural importation of works by American gay artists such as Robert Mapplethorpe and Edmund White. As Japanese publishers sought to exploit this new interest in gay art created by gay artists, Tagame emerged as an influential artist on the basis of his work at June, Barazoku, and other magazines. Tagame made his debut as a gay erotic manga artist in 1987, creating manga for Sabu. In contrast to the heterosexual and female-oriented yaoi and BL magazines that had published Tagame's previous works, Sabu was produced by gay men for a gay male audience. His manga series The Toyed Man (嬲り者, Naburi-Mono), originally serialized in the gay men's magazine Badi from 1992 to 1993, was published as a book in 1994 and became the first gay comic work in Japan to turn a profit. The breakout success of The Toyed Man demonstrated the viability of gay manga – manga about gay relationships for a gay male audience, in contrast to yaoi – as a commercial category, and established it as a genre "of cultural merit and artistic importance." Tagame's second longform series, the 824-page, three-volume historical epic The Silver Flower (男女郎苦界草紙～銀の華, Shirogane-no-Hana), is noted by Graham Kolbeins as widening "the scope of what gay manga could be narratively" beyond stories focused largely on pornography to incorporate complex narrative and aesthetic elements.

In 1995, Tagame and two editors from Badi founded the gay men's magazine G-men, a shorthand for "Gengoroh's Men". The magazine focused on works depicting masculine, physically large men, and featured manga depicting older and muscular body types. G-men was part of a concerted effort by Tagame to "change the status quo of gay magazines" away from the aesthetic of bishōnen – delicate and androgynous boys and young men that were popular in gay media at the time. G-men was a success, and by 1996, Tagame was working full-time as a gay manga artist. The magazine serialized the bulk of Tagame's manga published during the 1990s and early 2000s, notably Do You Remember the South Island's POW Camp? and Pride. Tagame continued to publish his serialized manga as books during this period, initially through gay pornography production companies, and later through formal publishers. Beginning in 2003, Tagame began publishing the multi-volume gay erotic art anthology series Gay Erotic Art in Japan, which follows the history of Japanese gay erotic art from the 1950s to the present.

Tagame attracted an international audience beginning in the 2000s though the circulation of pirated and scanlated versions of his works. His works began to receive officially-licensed translations in 2005, after French publisher H&O Editions released a translation of his manga series Gunji; an exhibition of his works was held in Paris in 2009. In 2012, an English-language translation of Tagame's one-shot manga Standing Ovations was published in Thickness, an erotic comics anthology published by Ryan Sands and Michael DeForge, marking the first release of an officially-licensed English-language translation of Tagame's manga. American publisher PictureBox published The Passion of Gengoroh Tagame, an English-language anthology of Tagame's manga, in 2013; several of Tagame's works were also translated into English by the now-defunct publishing house Bruno Gmünder Verlag.