Sexuality is polymorphous. It has to be. This is because — rightly or wrongly — it often faces rigid repressive structures that it can only outflank by changing its forms and pouring its energy in new directions.

Sigmund Freud wrote about artistic creation as the sublimation of sexual drives into forms far removed from their original motive power. But art has also provided a convenient license to those who didn’t want to sublimate their sexuality, choosing instead to parade it beneath the thinnest of veneers. Even in what we consider the prudish Victorian era, artists could get away with salacious, full-frontal nudity — as long as they gave it a pleasant classical or mythical name.

At first glance, the 100 or so works by Iwami Furusawa (1912-2000) at the Itabashi Art Museum, suggest an artist of the second stripe. His nudes, which make up the bulk of exhibition, lack classical purity and gritty realism in equal measure. Painted with a bright and vibrant palette and thrown into passionate, suggestive and stylized poses, Furusawa’s women seem designed mainly to titillate and perhaps test the censorship laws of an earlier age.

“He was arrested twice for obscenity,” Satoko Hironaka, a curator at the museum, told The Japan Times. “Once in 1964 for an exhibition catalog, and once in 1969 for a book illustration.”

What makes these saucy works even more enjoyable are the occasional elements of the mythic and surreal thrown in as if to say, “This is not porn. This is . . . ahem . . . serious art.”

An enticing picture of a bare-breasted, dark-eyed maiden, holding what looks like a glass of creme de menthe, is given the respectable name “Daughter of Bacchus” (1983), while “Trojan Women” (1997) uses the classical statue of Laocoon and his sons being attacked by a serpent to create an odd, sexually charged scene of two naked, milky-skinned, golden-haired lovelies, a withered crone and a snake.

Hironaka does not deny the obvious sexuality of these paintings, but sees it as an expression of the painter’s philosophy, which was based on his experience as a soldier in China during World War II, where he became a prisoner of war.

“He saw many soldiers die in China,” she says. “So, he wanted to paint about the pleasure of being alive. He often said the world is destruction, but women are regeneration. Some people say his art is porn, but I think it’s about regeneration.”

It’s a nice theory, and almost works with a painting like “Woman from the Northern Country” (1958), in which the somber subject’s poise and thoughtful gaze, in conjunction with a desolate fish-strewn background, hints at a deep, dreamlike meaning. But the use of Surrealist elements by Furusawa, as with many Japanese painters, is more about invoking the freedom of art than pointing to anything deeper. In his case, the freedom allows him express a certain Bohemian hedonism.

This view sits more naturally with the majority of his work, in contrast to the more respectable regeneration theory, which sounds positively absurd when juxtaposed with certain of his racier pieces. The theory would have had more legs if Furusawa had actually painted women “regenerating” — that is, having, nurturing or caring for children. Instead, apart from the occasional portrait of his wife and a strange bird-women motif, practically all the women are presented as young, naked, exotic and, to use the vernacular, “begging for it.”

Also, because his attention is on the alluring and transitory elements of fashion, hair, makeup and posture, rather than timeless elements of physique and physiognomy, many of the works have the dated, almost nostalgic quality of pictures from old copies of Playboy or Penthouse — albeit with a Parisian twist.

But the problem here is not Furusawa’s choice of subject matter. This merely reflects his sincere interests and reveals a male aesthetic that, despite objectifying women in terms of sexual desire, is as valid if not more so than theories of sexual deconstruction cherished by some feminist artists. The problem, rather, is the way we feel the need to segregate art from porn, despite that there have always been elements of the one in the other.

“I think porn is commercial but art is expressive and has a message from the artist,” Hironaka says. Many have struggled with this tricky but hollow dilemma. My solution is to ignore the distinction and to instead focus on the strong lines, bright colors and obvious enthusiasm with which Furusawa painted his vamps and sirens.