Mixi is a Japanese social network founded by Kenji Kasahara in 2004.
Mixi enjoyed great popularity right from the start. In 2005, after just one year, the network already had more than one million users. One year later, it was already 5 million. By March 2012, user numbers had risen to 27.1 million .
Similar to other social networks, Mixi offers a multitude of functions so that users can exchange information. These functions include:
Mixi is mainly based on open source software and uses Linux, Apache, MySQL, Perl, Memcached, Squid and Shard. The company has over 100 MySQL servers in use and adds at least ten each month. Mixi uses 39 computers with a memory of 2 GB for caching. 
A Japanese mobile phone number is required to register with Mixi. Thus, anyone who does not live in Japan is excluded from the network. Since 2012, the service has provided a mobile app for Android and Apple devices. Each account can accumulate a maximum of 1,000 friends (called myMixi).
Mixi was criticized in 2008 when the social network announced an adjustment to its terms and conditions. The adjustments stated that users should confirm that the rights to all information they post, including photos and other data, should be transferred to Mixi. However, due to protests by users, these terms and conditions were not implemented. To this day, all rights for the posted content remain with the original owners.