Thats the Nakagin Capsule Tower. It was designed in 1970 by Kisho Kurokawa. It faces the danger of demolition.
Here is the web page of Kurokawas office: http://www.kisho.co.jp/page.php/209
For other photos check my website: http://picasaweb.google.com/dionisiofranca/KishoKurokawaSNakaginCapsuleTower#
Check also this video on youtube: