PARIS – Looking around before “Ai no Uzu” began, there was an almost palpable anticipation ahead of our plunge into the realm of young Japanese people’s sex lives. What to talk about while waiting for the orgy to begin?

The excitement was less to do with the exotic, though the audience was mainly French, than with an excited nostalgia that seemed to be buzzing beneath all those fashionably graying locks and balding pates in the Maison de la Culture du Japon’s elegant auditorium.

To calm us as surreally thumping beats pounded out, we were given a questionnaire to fill in later — though some at once wrote that the “music” was simply insupportable.

But when the curtain rose and we saw the on-stage apartment, such concerns fell away along with the decibels as we took in every detail. It was like peering through “a window onto an unknown world,” as one woman told me she commented on the questionnaire.

Its multi-dimensional framing was a standout feature of the piece: the set is an ingenious series of rectangles that each momentarily holds our attention, pulling us from one side of the stage to the other.

The play opens with two characters talking, facing each other across a counter and framed by a small, almost imperceptible, reproduction of Leonardo’s “Last Supper” to their right. The rest of the visual frame is filled by doors — one to the exterior, an inner door, the toilet door, one to upstairs and another to the shower. Above this are cement walls, the perfect place on which to project the script’s French translation (one of the best solutions I’ve seen to this perennial challenge). Then upstairs, the windows open to what the boss of the house calls the “play room,” with three single beds — no place for pre- or postcoital lingering.

Indeed, time was ever-present, as if it was unfurling in true temporality as the two-hour play takes us from 10 p.m. to 5 a.m., with a “flashback” to 9 p.m. When there is an elision, Renaissance paintings, their gold frames included, flash across the backdrop. The frozen moment of the Pietà, of the mother of Jesus holding his lifeless body, pushes us to the next hour, the next partner.

This image of unconditional love is in binary contrast with the tawdry “love” the eight central characters are wrestling with — four women and four men, though the first male we see has a more feminine role and look. In the program notes, the writer/director, Daisuke Miura, says the play’s title conveys no sense of the piece itself. While this may be true in French and Japanese, the English title, most often rendered as “Love’s Whirlpool,” seemed to exactly describe what was going on. In particular, the word “whirlpool,” more than “love,” seemed quite le mot juste, since the former conjures up images of a washing machine into which everything is thrown together, goes around and around, and at the end is left limp, damp and not necessarily clean.

For his part, Miura, 39, explains that the course of the play allows each person to adlib and find their own interpretation of love depending on personal preferences.

There was, too, a visceral connection with the audience, and when the cast members — who on stage are also caste-like, each with a designated persona — are blinded by the morning light, myself and those around me all flinched at the sudden brightness.

In Japan, Miura is a star; in 2006 he won the country’s major theater prize, the Kishida Kunio Award, for “Ai no Uzu,” and he is always portraying young people’s lives. His scripts are freeform and his directions general, leaving the actors to fill in the rest.

In a 2007 interview with the JT’s drama writer Noboku Tanaka, he explained that he would append in the script, “Actors make suitable conversation,” and I can’t help wondering if awkward exchanges in the play about the flu fell into this category. Images of their bodily fluids were already too vivid.

In October, the Guardian ran one of those breathless stories about young Japanese losing interest in sex, describing “celibacy syndrome” (sekkusu shinai shokogun). A former dominatrix also told how her first task with new clients was to get them “to stop apologizing for their own physical existence.”

It is the physical that Miura is exploring as his varied characters each give voice, in their own “frame” of background and context, to how they came to be paying for sex or their need to touch somebody in this club where they don’t know anybody.

Establishments like the one here do exist, and just a few years back CNN Travel ran a story on such places dubbed “happening bars.” In “Ai no Uzu,” we are transported to such a club when the lights come on. Shown as the voyeurs we are, we have just spent two hours watching a group of young people awkwardly exchange themselves, change themselves and try to work out how to put aside, in the bag with their clothes, their much heavier cloaks of politeness — and find their voice. There is a delicious moment where a portion of them comment on the orgasmic moanings of another, on how they can really see her now.

A little like the group on stage, my fellow onlookers in the very intimate 232-seat auditorium all seemed a little shamefaced, nobody quite catching anyone else’s eye. The reception was warm, if somewhat restrained, though the overwhelming written response was positive, hailing the piece as realistic and original, “a whirlwind trip, a game of bingo.”

Miura is currently putting the finishing touches to a film version of the play — I hope he can retain the voyeuristic, shared narcissism that gave the stage version I saw such teeth.