---Airport pickup is one option. These links may be helpful, too:
(1) SIM for 30 or 60 days, http://www.so-net.ne.jp/prepaid/en/index.html
(2) SIM for 7 days or 14 days, http://service.ocn.ne.jp/mobile/one/visitor/en/
(3) App for Free WiFi Search, http://www.ntt-bp.net/jcfw/en.html
comparing several companies in 2014 this one seems to have one of the most competitive prices:
http://en.wifi-rental-store.jp/
(1) SIM for 30 or 60 days, http://www.so-net.ne.jp/prepaid/en/index.html
(2) SIM for 7 days or 14 days, http://service.ocn.ne.jp/mobile/one/visitor/en/
(3) App for Free WiFi Search, http://www.ntt-bp.net/jcfw/en.html
comparing several companies in 2014 this one seems to have one of the most competitive prices:
http://en.wifi-rental-store.jp/