Facebook's Japanese site is catching up to homegrown competitor Mixi with the announcement that it has 10 million active users. This is up from the 5 million active users reported in September of 2011. The number means 10 percent of Japan's web users are actively using the service, with the number of registered users estimated around 15 million.
Mixi currently has around 15 million active users, but if Facebook's growth continues at this pace, it could pass Mixi before the end of 2012. This means Japanese developers will need to start focusing on Facebook as much as American developers have for the past few years.