From the exterior, the building is an ordinary three-storey office surrounded by upper-middle-class homes in a respectable suburb of Tokyo. A convenience store is on the corner of the road and the local town hall just a stone's throw away.
The neighbours have no idea that some of the most powerful marijuana available in Japan is grown in the basement of the building by a 'businessman' who lists among his clients some of the most famous singers and television stars in the country.
'Drugs have become more fashionable in the last couple of years,' the man, who will only identify himself as K, told the South China Morning Post.
'In the US and other countries, marijuana has been considered fairly harmless for years, but it was not like that in Japan. Now, people think of it just like tobacco or having a drink.'
And that attitude has been driven by faces that are familiar to all Japanese getting into trouble with the police for possession.
'For celebrities, acting bad is cool, and they're always bragging about how they know a dealer or how they can always get drugs,' K said - and he rattled off the names of three very famous Japanese 'talents' that are his customers. 'And that makes kids want to try it as well.'