Every resident of Japan - including foreigners (who have legally resided in Japan for more than 3 months) will be assigned a new number "My Number" that will be used for all social and tax services of the Japanese Government. This system will start from January, 2016 and everyone will need to apply for an "Individual Number Card".
Please check the official information from the Japan Cabinet Secretariat:
http://www.cas.go.jp/jp/seisaku/bangoseido/english.html
Thanks Devendra Narayan san for sharing this news