Tokyo’s newest and biggest visitor attraction, the 634-meter-high Tokyo Sky Tree in Sumida Ward, will open to the public on May 22. And if 11th-hour contract negotiations bear fruit, visitors to the Sky Tree may soon have the opportunity to plummet 430 meters (over 1,400 feet) toward terra firma, in what is claimed to be the world’s highest commercial bungee jump.

Falling for it: While shooting the Tokyo Sky Tree at night, Japan Times photographer Yoshiaki Miura captured a test jump for the planned Big Bungee Banzai attraction.YOSHIAKI MIURA

The new service, it was learned, has been quietly undergoing safety tests late at night. If arrangements can be finalized within this month, the first customers may be able to take death-defying dives from the Sky Tree from around mid-June.

The jump was discovered after being inadvertently photographed by The Japan Times’ sharp-eyed senior cameraman, Yoshiaki Miura, who was in the neighborhood shooting night exposures of the new tower.

“I didn’t notice anything at all until I uploaded the pictures into my computer the next day,” Miura said with a grin. “That’s when I saw this grainy line across the computer monitor and I thought, ‘Oh, damn — something must have streaked my lens filter.’ I was going to delete the photos but then I zoomed in and scrolled all the way to the bottom, which is when I realized I’d captured a bungee jumper in what looks like a Spider-Man costume.”

When this columnist confronted the Sky Tree front office with Miura’s photographic evidence, the PR staff at first refused to confirm or deny this claim, stating the image on film showed one of the nighttime cleaning crew who had fallen off a gondola and was saved by his safety harness.

Two days later, however, the tower’s operator phoned and provided off-the-record details of its negotiations with a concessionaire.

Because the project is still tentative, it has been kept under heavy wraps. To maintain secrecy while the negotiations are underway, test jumps have been conducted in the small hours of the morning, starting in January.

“The test jumps were made after midnight on nights when there was no full moon,” says Nobinaga Tobishima, acting manager of Botan Ltd.’s New Business Development Group. “The male and female test jumpers wore all-black, nonreflective clothing resembling ninja costumes. We suspected it might have been possible to catch a glimpse of them, but only under ideal conditions.”

Safety has been a major concern, and the jump’s operator has agreed to a governmental condition that services will be suspended when wind speed exceeds 8 meters per second, as well as providing strict screening of would-be jumpers.

The operator also agreed to impose rigid safety requirements. Jumpers will be limited to healthy persons who have passed an on-the-spot EKG (electrocardiogram), are aged between 18 and 45, and have a body weight of at least 40 kg. New-style bungee cables composed of special carbon fiber materials, developed by Japan’s aerospace industry, will be used, and jumpers will be fitted with special safety gear, including a newly designed harness incorporating what is claimed to be the world’s first gravity-activated airbag. In order to discourage late-night revelers from taking the plunge, would-be jumpers will also be required to pass a breathalyzer test to indicate Blood/Breath Alcohol Concentration (BAC) is below 0.06 percent.

Jumpers will receive a commemorative certificate with their name inscribed and a T-shirt emblazoned with “Death-defying 430-meter dive. I watered the Tokyo Sky Tree.”

The price for being allowed to perform the stunt has yet to be determined, but will reportedly include an injury and life-insurance premium. Jumpers will also be required to sign a form waiving liability beyond the amount insured.

Initially the proposal for the new concession is said to have faced strong opposition from groups within the ruling and opposition political parties. Selective appointments to the board of directors have overcome this. The board now includes three senior bureaucrats from the Ministry of Education, Culture Sports, Science and Technology; two from the Ministry of Land, Infrastructure, Transport and Tourism; and one each respectively from the Ministry of Finance, Ministry of Economy, Trade and Industry, National Police Agency, Ministry of Justice, Ministry of Foreign Affairs, Ministry of Defense and Disaster Management Agency.

Indeed this large presence of retired bureaucrats led one wag to suggest the new concession be nicknamed “The Amakudari” — a term meaning “descent from heaven” that is typically applied to the system by which retiring government officials land cushy second careers in the private sector.

Choosing a name for the death-defying plunge has caused some head-scratching. After considering such selections as Sky Tree Drop; Tokyo, Here I Come; and Geronimo Giant Jump, the directors settled on Big Bungee Banzai as the name of the attraction.

The spokesperson for the operator said it estimates demand for T-shirts, coffee mugs, postcards and other licensed spinoff goods such as cellphone ornaments will reach ¥310 million in the first year alone.

Bungee jumping is believed to have originated in primitive societies, as a test of courage and a rite of passage into manhood. The ritual is practiced by the natives of Pentecost Island in the south Pacific nation of Vanuatu. The indigenous Papantla people of central Mexico have a similar practice.

The world’s height record for a bungee jump is believed to be held by Andrew Salisbury, who in 1991 jumped for 2,700 meters from a helicopter over Cancun, Mexico, for a television program sponsored by a sports shoe manufacturer. The full stretch was recorded at 962 meters. He then landed safely by parachute.