In a ukiyo-e style woodblock print by the Edo-period artist Suzuki Harunobu, two couples frolic in a brothel, seemingly lost in separate worlds. A female prostitute playfully tweezes the mustache of her male companion in the background; in the foreground, another prostitute cradles the head of a coy woman holding a folded fan — or rather, a figure who resembles a woman but is, in fact, a young man.

Such misidentifications of male adolescents, known as wakashu, in Edo-era prints were long made by many scholars, as the figures were depicted very similarly to young woman, with delicate features and long tied-up hair. Yet some have noticed that the artists actually carefully employed specific visual devices as gender cues, with certain details intended to distinguish youthful wakashu from other individuals. An eye-opening exhibition at Japan Society closely examines the representations of wakashu in more than 65 woodblock prints drawn from the collection of the Royal Ontario Museum (ROM), where it was initially displayed last year in the first show in North America devoted to wakashu. As its title suggests, A Third Gender: Beautiful Youths in Japanese Prints argues that wakashu comprised a gender of their own, as defined by biological sex, age, outward appearance, and their role in an established sexual hierarchy, that was unique to this period. These young males were not only depicted as sexually ambiguous in art but were also, in the real world, objects of desire to both adult men and women.

“[The show] explores a social structure and cultural system that does not fit with gender binaries and heteronormative sexuality,” curator Asato Ikeda said at the press preview, adding that she hopes it will invite viewers to “think differently about sex, gender, and sexuality and to reflect on our own social practices and current gender politics.”

Wakashu referred specifically to males who had yet to go through the traditional Japanese coming-of-age ceremony known as genpuku. Although they did not carry the social responsibilities of adults, they were considered sexually mature. Their most discerning feature is their hairstyle: a slightly shaven crown flanked by side locks. (To signify having reached adulthood, a man would shave his entire crown, leaving a bald area with side locks intact.) This is best observed in a print on view by Hosoda Eisui of a wakashu holding an ornate shoulder drum. Hairstyles may seem, today, like a trivial way to understand gender, but they comprised an essential visual code in traditional woodblock prints. Combs and hairpins were shown to identify young women, and females, in general, had very elaborate hairdos.

Many colorful and stunning prints focus on wakashu alone, going about their daily lives as merchants, musicians, fishermen, and even samurai. One example of a red-lipped fan-seller in a translucent blue kimono exemplifies the need for a careful eye to discern between men and women.

More fascinating, though, are the prints that spotlight the relationships between wakashu and others. Some occur in the pleasure districts, which were under strict governmental regulation, where wakashu mingled on the streets alongside beautiful geisha and older samurai — the latter identifiable by long-sleeved kimonos known as furisode. Interior views of brothels and private parlors, as seen in erotic prints known as shunga, illustrate how these relationships adhered to established societal attitudes: While same-sex relations between two adult men or two wakashu were not condoned, adult men and wakashu were allowed to be together due to their age difference, which bred a particular sex and gender regime. In prints, a clear power dynamic is always present, with bald men dominating wakashu, who in turn are depicted dominating their female partners — although works also exist of much older women having the upper hand. One such image, attributed to the Utamaro School, shows an eager lady throwing herself on top of a startled wakashu, her hands firmly clutching his shoulders.

Although criticized, homosexuality was practiced for centuries among samurai as well as kabuki actors, where the stage hosted literal performances of gender. Cross-dressing was widespread in kabuki, which makes it difficult to differentiate between men and women in prints. Adult male actors would take on female roles but would also appear as wakashu; wakashu would cross-dress as women, who may have assumed manly appearances. A painting of five dancers exemplifies the gender ambiguity that would emerge on stage: The mustachioed figure on the far right is clearly a man, but the others are probably a mix of women and wakashu.

Some scholars argue that such confusions likely added to the visual pleasure of the owners of these works, who were primarily adult men. The exhibition raises the question of whether prints of wakashu, who were younger than 18, could be considered a form of child pornography; Ikeda argues that they don’t, as the works do not represent specific individuals. As for the actual acts that occurred centuries ago, they were acceptable at a time when sexual relationships occurred at an earlier period of one’s lifetime — which was much shorter — and when there was no established age of consent.

The exhibition demonstrates that while visual signifiers of gender manifest clearly in these prints, gender and sexual expression in traditional Japanese society was fluid and complex, transcending binaries. One of the most memorable prints in A Third Gender features no wakashu at all, centering on two women on a couch with a dildo. According to Ikeda, they are likely ladies-in-waiting, who were unmarried and encouraged to pleasure themselves in their quarters. The script surrounding them is explicit: “Let’s do this position again” and “I came twice already, but I want to come again,” the characters read. Homoerotic desire between women during the Edo period remains largely unexplored, as there isn’t much literature on female romance or lesbianism; what researchers do know, however, is that the print was most likely designed by a male artist, as many were. It’s a reminder that some of these prints may be less records than fantasies rendered for the enjoyment of adult males.

Wakashu is, of course, a historic term, and gender relationships in Japan have certainly changed drastically since the 1700s. This “third gender” became obsolete by the second half of the 19th century, when notions of gender and sexuality changed as the arrival of the US Navy pulled Japan out of isolation from the Western world. Along with increased trade came new values, with heteronormativity as the norm.

Thought-provoking as well as visually splendid, A Third Gender peers back in time to shed light on a figure key to understanding a history of complicated desires, one prevalent as an artistic subject but with a message that has remained quiet for a very long time.

A Third Gender: Beautiful Youths in Japanese Prints continues at Japan Society (333 E. 47th St, Midtown, Manhattan) through June 11.