It seems that all is not great with Jamiroquai's visit to Japan at the moment. The band flew out to Japan on Thursday for the Summer Sonic concerts in Osaka on Saturday and then in Tokyo on Sunday.
Bad weather has caused delays to performances and re-scheduling but it now seems (thanks to j-love.info) that the performance at least today in Osaka has been cancelled due to illness, and that this was before the weather starting messing around with the schedules. This has also been confirmed by the organisers on their twitter feed.
If anyone has any further updates or information then please feel to post a comment with this news item. In addition to the Summer Sonic concerts in Japan the band are set to perform in Seoul in Korea on Wednesday (22 August).