Beekeeping project on the city’s roofs among series of moves to improve the ecosystem.
Japan will provide $2bn over three years to help developing countries save their ecosystems, the country’s prime minister has announced.
Naoto Kan made the pledge at a UN biodiversity summit in the central Japanese city of Nagoya on Wednesday.
It came amid a growing environmentalist movement throughout the country.
Steve Chao reports from Tokyo on efforts to make the city green.