The office tower would not look out of place in any central Tokyo street: from its glass entrance door and sweeping marble lobby to the ear-popping lift with its steady influx of salarymen. But this particular building is not only abuzz with the activity of its grey-suited workers. Its rooftop is home to a less conventional breed of tenants: more than 300,000 honeybees.
As one of the most densely populated cities in the world, Tokyo may be more famous for its concentration of human beings than for its status as a home for bees. However, the urban honeybee is flourishing in the metropolis. Once associated with strictly rural environments, the world's honeybee population is in crisis. Fuelled by a complex cocktail of problems ranging from climate change to the use of pesticides in rural areas, a global decline of the honeybee has gathered pace in recent years.
This week, the British Beekeepers Association reported that a fifth of the UK's honeybees died last winter, with populations dropping by up to 15 per cent over the past two years. Meanwhile, honeybee populations in numerous countries around the world similarly declined by around 30 per cent last year, according to the International Bee Research Association. The decline of the honeybee has led to experts making increasingly vociferous calls for urban dwellers to take up beekeeping in cities where pesticide contamination is low and honeybees are able to flourish.
Among the most famous of the urban beekeeping aficionados is Scarlett Johansson, who received a hive of the animals from Samuel L Jackson as a wedding gift. Testimony to the rise of the urban beekeeper is the success of Tokyo's honeybee project on a rooftop in the heart of the upmarket Ginza area of the city. Here, in an area more famous for its architect-designed fashion towers, historic department stores, crowds of shoppers and the most expensive commercial rental space in the capital, the honeybees are thriving.
Fortified by nectar from pesticide-free flowers grown in the nearby Imperial Palace gardens, inner-city parks and the odd rooftop garden, the collection of 20 hives of bees has produced more than 760kg of honey so far this year. The honey produced is used in cakes sold at the nearby Matsuya Department Store as well as desserts prepared at a string of local restaurants and cocktails in the neighbourhood's upmarket bars.
The man behind the Ginza Hachimitsu (honeybee) Project - dubbed Ginpachi - is the 51-year-old Atsuo Tanaka, whose official work consists of operating a real estate company specialising in conference space from his fourth-floor office. Until three years ago, Tanaka's experiences of honeybees were strictly confined to the more conventional activities of eating the sweet stuff and the occasional encounter with the flying insects on a golf course.
However, when he was approached to help a professional beekeeper find a location in the capital to set up a beekeeping project, his interest was instantly piqued. "I come from Tokyo downtown and have never had much experience of dealing with nature's insects. The closest contact I had with nature in the past was limited to golf courses," he says. "But then I met a professional beekeeper and it occurred to me that the roof of our office building might be a good place. I took him up here and he suggested that we set up our own project. He explained about the plight of the honeybee and how the Japanese industry is in trouble."
Problems particular to the Japanese honeybee include widespread deforestation to make way for construction work resulting in a shortage in bee-nurturing flowers across the countryside. Add to that the effects of being dramatically weakened by widespread pesticide use by farmers, and the Japanese honeybee is in serious trouble, says Tanaka. "The professional beekeeper explained all of this and said if you start making honey in the middle of Tokyo, it could have a very big influence in helping sustain the beekeeping industry."
He adds: "At first I thought why me? What a crazy idea. But it all made sense - and I decided to give it a go." Tanaka is explaining this as he makes his way to a weekly Saturday morning honey-collecting session with a group of bee-loving volunteers. Having entered the pristine confines of his 11-storey office tower, he has bypassed his fourth-floor office and instead taken an lift to the top of the building before completing the final journey to the roof via a steep staircase.
At the apex of the building, the views over the Blade Runner-esque Tokyo skyline consist of a breathtaking jigsaw of gleaming skyscrapers, neon lights and tall tower blocks. But competing with the vistas are undoubtedly the honeybees. In one corner of the roof, behind makeshift plastic walls that appear more decorative than functional given that there is no roof, are piles of wooden boxes firmly tied with rope - inside which hundreds of thousands of urban honeybees reside.
After tucking his socks into his trousers ("You don't want them to fly up your leg," he chuckles) and stepping into his all-in-one white body suit complete with a straw hat covered with a net, Tanaka joins a clutch of four similarly clad volunteers. Among them is Naoko Yamamoto, a pretty 35-year-old whose love of the sticky nectar has prompted her to give up a job as an office lady to train as a professional apiarist.
Tucking a pink scarf under the netting of her straw hat, she says: "I love honey. I have honey for breakfast with yogurt, with lemon tea in the afternoon and evenings. My kitchen is full of honey. It's my number one favourite thing. "My dream is to open my own hives in the middle of the city." Nearby, Toru Katagiri, 45, a soft- spoken worker from a chemical company, is watering a collection of organic plants growing on the roof - from basil and southern Japanese goya vegetables to tomatoes and sunflowers - before he tends to the bees.
"I started coming here three months ago because I was curious about how honeybees could be living in the heart of a city," he says. "I was so surprised when I saw that these bees were making 20 kilos of honey a week from a rooftop in Ginza. "I enjoy coming here - it's relaxing and very different from my normal job in a chemical company." After uttering the reassuring words "I maybe get stung once a week, sometimes not at all", Tanaka leads the motley honeybee lovers into the hive enclosure and sets to work.
First step? Untying and opening all the boxes, inside each of which are slotted eight sheet-like frames of honeycomb and an estimated 40,000 sugar-high honeybees. After seeing how much honey has accumulated and making care not to disturb the queen bee - of which there is one in each box - the team gently brush the bees off the honeycombs. On the corner of the rooftop, a mechanical contraption is then used to drain the honeycombs - and before long, a clear gold stream of nectar starts trickling into a large vat.
Armed with only silver canisters emitting streams of smoke for protection, the honeybee brigade work painstakingly slowly in order to ensure that the bees are not disturbed. "There are more than 300,000 honeybees on this roof and only 120,000 residents living in this district in Tokyo - that's nearly three times as many bees as humans," says Tanaka as he methodically sprays one bee-covered honeycomb with vinegar to keep the animals healthy.
"Some people are fearful of the thought of thousands of honeybees in the city. But they are not dangerous. They rarely sting. They are quite soft creatures; they have good characters. And they are very happy today - they haven't stung me once. "At first, we had to persuade the other offices in the building and the local authorities that it was a good, safe idea to have honeybees here - and since we started up, we have not had a single complaint."
At least 10 companies in Ginza have started planting rooftop flower gardens to create nectar-rich enclaves as part of the project. "The city is actually a very good place for honeybees," says Tanaka. "The flowers that are grown here are not affected by pesticides like in the countryside. "Honeybees don't live for very long - only 30 to 40 days - so there is not enough time for city pollution to affect them. It is a great environment for them to make honey.
"Working on this project has made me realise that the city is not just about humans. There are bees and butterflies and all sorts of other insects living alongside us." Sticking his finger into a honeybee-covered honeycomb before sticking it in his mouth, he adds with a smile: "And it means I can eat lots of honey, which I love." As a voluntary non-profit organisation, the welfare of honeybees rather than financial success is firmly at the top of the agenda of the Ginpachi collective.
Although the project has attracted commercial offers from companies both in Japan and overseas - one recently visited from Dubai - they are currently focusing on distributing honey in a sustainable fashion within the community. Later, as Tanaka sits by the edge of the roof terrace decanting the day's honey catch into plastic bottles, he says: "This is not about making money, it is about educating people about honeybees and creating an environment in the city where they can make honey.
"We make more than 700kg of honey a year at the moment with 20 hives. But we want to increase this to three tonnes a year with maybe 30 hives eventually." Surveying the urban panorama of endless skyscrapers before him as he continues to fill bottle after bottle with clear honey, he adds: "This is just a dream at the moment. But cities such as this may be key to helping save the honeybee in the future."
For more information about Ginpachi, visit www.gin-pachi.jp.