Takashima Ryozo's "Artman Ship," a springwater-filled monolith by Zenpukuji's pond		Nests of neckties in the trees: Yoshiaki Kaihatsu's "MENSU (Man's Nest)"

Zenpukuji Park is a little jewel of green space set in an otherwise nondescript residential area of western Tokyo. The park surrounds two ponds -- one a small, reed-filled nature preserve full of ducks, egrets and water lilies, the other a larger body of water that attracts flotillas of rent-a-boaters on weekends.

For the past eight years, Zenpukuji's big pond has been the site of a mysterious annual ritual. Sometime in spring or autumn, bizarre structures of indeterminate function suddenly materialize amid the surrounding footpaths and trees. Closer inspection reveals small signboards describing these apparitions in both Japanese and English. All are part of an art exhibition very aptly named "Trolls in the Park." Like trolls big and small, the contemporary works installed for the three-week duration of the event pop up in the most unexpected places, sometimes assaulting, sometimes bewitching the eye.

Whimsy is the prevailing mode. Some works interact or contrast with their woodsy setting to poignant or hilarious effect; others seem merely offhand, stereotypes of conceptual art at its laziest. Overall, what lingers longer than the impact of the individual works is the pleasure of strolling through a suburban oasis that has metamorphosed into a forest of wacky stuff. Still, certain installations do stand out on their own. Among this year's "trolls," some of my favorites were:

- Ryozo Takashima's "Artman Ship," a large plexiglass vat of water that stands sentinel-like by the pond and is filled and emptied at regular intervals (per a posted schedule) by the artist, who pledges "to carry as much water overland as possible during the exhibition from the Osonoi water source to the start of Zempukuji River ... so that the water is not slowed down by the passage through Zempukuji Lake."

- Yoshiaki Kaihatsu's "MENSU (Man's Nest)," a grove of trees festooned with birdhouses from which neckties dangle like an aviary of tongues. Kaihatsu says: "I had an image for a work that combined a necktie with a bird's nest. The birdhouse is a metaphor for the dwelling environment of Tokyo. However, it can also be said that it is just the combination of a necktie and a birdhouse."

- Reiko Akatsuka's untitled installation of oversize manga speech balloons, filled with telephone receptionist non sequiturs -- Japanese equivalents of "Thank you for waiting," "May I help you?" and the like -- or sound effects, like the GACHA! of a receiver being slammed down. All of these emanate, seemingly at random, from benches and bushes surrounding an archetypal park statue of a turn-of-the-century city father. Unlike most of the other artists in this exhibition, Akatsuka provided no comment on her work.

The organizer of "Trolls" is a remarkable neighborhood institution, Youkobo Art Space (Youkobo means literally "studio of play"). Founded in 2002 by Hiroko and Tatsuhiko Murata, it occupies a small complex that was once a tuberculosis sanatorium and later an animation studio. Hiroko Murata, herself a sculptor, had a number of non-Japanese students and had seen successful artist residency programs in action on visits to Europe. The Muratas decided to start their own residency program, and since then Youkobo has provided a toehold in Japan for around 100 artists from 15 different countries. With two apartments and attached studios that can accommodate up to four residents at a time, Youkobo hosts ten or twenty artists a year for periods ranging from one to six months. Besides the two open studios exhibiting the residents' work, another gallery space features young Japanese artists, encouraging the interaction of domestic talent with the visitors from abroad.

While running its residency program, studios and gallery, Youkobo manages to find time to organize "Trolls in the Park" every year. One of the benefits of the art space's international outlook (and non-Japanese staff) is that it produces excellent bilingual materials on all its exhibits. Hence a stroll with the trolls in Zenpukuji is a very foreigner-friendly experience, more than can be said for a visit to many Tokyo museums.

"Trolls in the Park 2009" ended on November 22. Although the dates for its return to Zenpukuji in 2010 are not yet set, plans have already been made for a Trolls exhibition in London's Canizarro Park from May 7 to 11.

Rieko Akatsuka's untitled installation of cartoon speech balloons and sound effects, surrounding a statue of local luminary Hidegoro Uchida The façade of Youkobo Art Space in Zenpukuji, Tokyo All photos by Alan Gleason, courtesy of Youkobo