Japanese culture has long had an ambivalent relationship with erotic art, loving it secretly, but never exhibiting it openly. A current exhibition, titled Shunga (literally "spring pictures," a long-standing Japanese euphemism for erotic paintings), has overcome a number of restrictions to present a phenomenal display of hand-painted works and ukiyo-e woodblock prints from the Edo period (1603-1867).

Because all the works are erotic, and many of them explicitly so, finding a venue for the exhibition was not easy. The Eisei-Bunko Museum, a foundation and collection housed in a rambling multi-story residence in Tokyo's Mejiro district, finally agreed to host the show, but only after a roster of researchers, professors and art specialists went public with their views about the importance and value of these works. The 133 masterpieces in the exhibition were culled from the British Museum, various Japanese museums, and university and personal collections.

An exhibition in 2013 at the British Museum, Shunga: Sex and Pleasure in Japanese Art, helped pave the way for showing these works in the country of their origin. About half of the pieces at the Eisei-Bunko Museum were also in that 2013 show. Works by Kitagawa Utamaro, Utagawa Kuniyoshi, Hokusai Katsushika, and other ukiyo-e masters demonstrate that far from being an unusual or unknown genre, shunga were printed, painted and distributed widely, if somewhat covertly.

The Eisei-Bunko Museum, which also contributed pieces from its own collection, stored away the other national treasures, important cultural properties, and antique books it normally displays to make room for these erotic works. Seeing them in the homey comfort of the museum seems somehow appropriate, especially since the display cases allow for close viewing despite the crowds in attendance. The curators have also provided excellent information and commentary (mainly in Japanese) on the background, social reception, and history of shunga.

Although a few Japanese exhibitions included such erotic works in the past, this is the first time that a full-scale show consisting entirely of shunga has been held in Japan. The result is an eye-opening introduction to an engaging and unique genre of Japanese art. The exhibition includes roughly 100 erotic ukiyo-e woodblock prints, including "bean-size" prints about the size of your palm, along with 38 brush paintings by ukiyo-e masters.

And to answer the question on everyone's mind, yes, the works are highly explicit. Graphic depictions of sexual intercourse, in all its myriad forms, comprise the central focus. However, the pictures also convey stories with as much visual, mental and emotional contact as physical. The portrayals of the surroundings and circumstances of the sex acts open a window onto the cultural values and social practices of the day. Many of the images are also extremely funny: this is the only exhibition this reviewer has ever been to in Japan where visitors burst into open laughter.

Laughing is appropriate, and in many ways, confirms the connection between Edo culture and contemporary attitudes. Shunga were as much entertainment, education, and stimulant as art. Collected works of various scenes were often given to newlyweds, friends, or customers in bordellos. However, the frankly sexual content can easily draw attention from the accomplished artistry of these works. The quality is stunning. One wonders whether the artists paid extra attention to their erotica -- or perhaps, because of the subject matter, they felt freer to innovate, with bolder lines, greater fluidity, and more distinctive compositions.

Many shunga are parodies of respected stories like Chushingura and The Tale of Genji, or of traditional scenes from classic poems and famous artworks. Even when not satiric, they suggest that sexuality is as much about setting, situation, and imagination as it is about physical urges.

The facial expressions of the subjects -- whether laughing, concentrating, surprised or entranced -- are especially captivating. Mouths open, eyebrows rise, hair loosens, and eyes close in ecstasy. Notably, the works do not portray the activity from the male point of view, unlike most commercial pornography, but present sexuality as a mutual interaction between equal and engaged participants, and as something gloriously deserving of artistic expression.

The value of this art is undeniable, making it hard to understand why it has taken so long to hold a special exhibit of these magnificent Japanese works inside Japan. It is a pleasure -- visually, artistically, historically, and culturally -- to see them brought together in so coherent an exhibition. Fortunately for residents of western Japan, a second show will be held in Kyoto from February to April 2016 at the Hosomi Museum.