Wandering the streets of the Marunouchi district - the business heart of the city - on a typical weekday evening would have been like walking through a ghost town a few years ago. Sandwiched between Tokyo Station and the Imperial Palace, the district is today shaking off its dull image and becoming the place to be seen. Chic restaurants are cheek-by-jowl with late-night shopping venues, bistros and bars. The key to the rejuvenation was a redevelopment scheme by Mitsubishi Estate Co - which owns the majority of the land and buildings in the area. Mapping out a 10-year, 500-billion-yen (HK$32.9 billion) project in 1998, the company has since completed a number of complexes that merge business and fun. It all started with a simple cafe, where anyone could use the internet for free, read magazines and attend meetings and events. The thinking was that Marunouchi should appeal to the young women - and their deep purses - who are setting today's trends. Making it more accessible and less intimidating has indeed drawn the crowds. The next step, announced in June, will involve Mitsubishi Estate lavishing a further 450 billion yen on a second, decade-long scheme from 2008. It will include a museum and a pedestrian square lined with European-style cafes. Constricted by the physical space, much of the development is inevitably going upwards. Most of the new skyscrapers are offices, but firms have been taking advantage of the fantastic views by giving the top floors over to restaurants. Unfortunately, the most important resident of the district - and, indeed, of the entire country - is not a huge fan of the changes on his doorstep. Concerned that one of his subjects might get a glimpse of the emperor pottering around the grounds of his Tokyo palace, the Imperial Household Agency has asked construction companies to redesign a number of new high-rise projects - to keep prying eyes at bay. Of particular concern is a 37-storey tower being planned. The palace has asked that no restaurant windows offer a view over the green roof of the imperial family's home or the sprawling complex of offices, shrines and residences. But the new building will be more than 1.5km from the palace moat, and diners would need exceptional vision to monitor the royals' movements. Mitsubishi Estate is still mulling over the palace's suggestions. Under a 1919 law, buildings close to the palace were limited to a maximum height of 31 metres, but the pressure on land today is such that the law has been scrapped. One of the earliest towers to be completed was the Marunouchi Building, in September 2002. It rose to 180 metres, and palace officials quickly realised that it offered a view over the walls of the palace compound. They responded by planting two tall trees atop the wall.