Last week’s launch of Twitter in Japan is showing early signs of success, reports ReadWriteWeb.

The new version was born when it was noticed that a significant percentage of Twitter usage was originating from Japan, despite the service being in English.

Now the dedicated Japanese version has been launched many sites are predicting an explosion of Twitter in the country.

Twitterlocal shows that Tokyo already has the highest usage of any city – almost three-times higher than second place location San Francisco.

Google Trends supports Twitterlocal statistics, as its stats show: Japan as the region with the highest overall usage, Japanese cities make up the top three globally and the Japanese language is the most prevalent across the service.

An interesting difference in the new version was the inclusion of ‘some commercial experimentation’ by Twitter. The Japanese service carries advertising media from two clients. The move has been interpreted by many of a sign of things to come for the rest of the service.