It appears that Tokyo curators have assumed a new duty as of late: that of thinking up catchy, metered titles for their exhibitions. First we had "Point of Purchase" at Parco, then "The Gift of Hope" at MoT, and now "The Place of Happiness" at the Watari-Um Museum of Contemporary Art in Aoyama.

Of the three, "The Place of Happiness" turns out as probably the most ironic. While the phrase implies that sort of playful and feckless fluff one sees too much of in Japanese contemporary art, the reality is that on first impression, only one of the show's four participating artists, Moshekwa Langa of South Africa, seems to have had any kind of fun in putting together his contribution, having opted to install a self-serve cocktail bar amid his collection of pencil and crayon drawings.

Langa's crude drawings, about 150 of them, are of things like rabbits and skeletons and the seaside, giving the walls the look of a kindergarten. And then there is the bar.

"Quite simply," says Langa, "I wanted to create an informal atmosphere. I decided that the drawings should not be framed, or presented in the usual way that museums would present drawings, but rather it should be like someone was coming to see my work in my studio, and I decided to put a bar in the middle so that people could have a drink. Also, there is background music playing (it was inaudible at the crowded opening), which is quite sentimental."

All right, that's fun, but what about the other artists? One is a wordy conceptualist resurrecting abandoned photographs, another a reticent young man with a cacophony fetish, while the third, recently deceased, has left us mementos of his dying days. Whither wandered the happiness?

Perhaps the best thing to do in approaching this exhibition is to first forget the title and take it as simply the latest offering from the Watari-Um, the always offbeat private museum that is practically a shrine to the likes of avant-gardists like Joseph Beuys and Nam June Paik. The funny thing is, by dismissing the premise, one may come to feel that the work in "The Place of Happiness" is circling around, perhaps at a distance but circling nonetheless, the different places where one might expect happiness to be.

Take Anton Olshvang's "found" photographs, for example. What the Russian artist did was tour the states of the former Soviet Union and call on photo-processing labs. There he purchased from bewildered but obliging technicians those prints that had been either machine-rejected for extreme over- or under-exposure, or customer-rejected because Uncle Vladimir was out of focus or his head was cut off, for example. Olshvang took these unwanted pictures home where he rephotographed them in a manner such that his windowsill or a piece of his carpeting became a "frame" around the outside of the photographs. The work, which brings a disquieting nostalgia, is some of the best in the show.

"It's a kind of psychoanalysis of society," explains Olshvang. "As an artist, I became a viewer of culture not only as a product of the conscious activity of society, but also of culture as a product of the unconsciousness of society. Values which do not belong to systems and society, but values that sometimes people belong to."

I told you he was a wordy conceptualist.

Upstairs one finds an interactive mixed-media installation by Japan-based Tam Ochiai, who is quick to comment that he "didn't really follow the title of the show" in putting together his suburban teenagers' rec room-style sound-based piece. Here a tangle of wires links a turntable with tape machines, a rock band mixing board and a cheap television set perched on a couple of milk crates, playing a channel-surf of old French films. There are a couple of guitar effects pedals out front that visitors are invited to manipulate to change the pitch of the loud soundtrack. The cacophony, as it happens, contains a fair bit of birdsong and laughter, which are happy things.

American James Lee Byars was preparing for this show when he died in Cairo in 1997 at the age of 65. There are a number of Byar's small objects and paper works here, as well as some correspondence between artist and museum. Particularly poignant is a collection of round papers, drink coaster-size, some 30 in all, with diary-like scribblings written over Byar's last months.

Surprisingly, they are anything but morbid. Reads one, "He should have everything he wants till his death." Others: "I boil water," and "Keep warm."

And finally, on the top floor, are Langa's drawings and self-serve bar, where it is always happy hour.

"Who knows," laughs Langa, "perhaps this really is the 'Place of Happiness.' "