Mobile phones, WiFi, and MiFi links
Everyone should have some means of connectivity while in Tokyo and this page has links on several options for phone service, wifi, and personal hotspots. The accommodations at FlexStay include wifi access, but I do not think we'll have access on the Sophia campus. In everyones' arrival package, I will be giving you a phone card that is usable for pay phones in Japan, however, these are pretty cost ineffective/inconvenient and are probably best regarded as a backup.
Your own phones
I tend to use the international package from my US carrier (AT&T), which allows me to use the Wifi networks of Japanese carriers. I have heard good things about T-Mobile for international packages but less positivity for Verizon. It is worth checking to see what your carrier provides, and reading forums about peoples' experiences with them while overseas.
Rental phones and personal wifi hotspots ('mifi')
There are multiple options for rental phones in Japan and I cannot vouch for particular providers. Below are some links for prominent ones, but I recommend doing your own research if you choose to go this route. Costs vary for phones with data capability or simply with calling, and for the type and speed of wifi connections. It is difficult for people on tourist visas to get a normal phone, but if you have a friend who is Japanese they can often add a wifi device to their existing contracts for a relatively cheap monthly fee.
Pururu (phone and wifi)
JAL ABC (wifi) and JAL ABC (phones)
Telecom Square (phone and wifi)
Japan Wireless (phone and wifi)
Global Advanced Communications (phone and wifi)
And Kakaku.com -- likely the cheapest, though the site is all in Japanese: Kakaku.com.
Free wifi out and about in Tokyo
The convenience store chain 7-11 and Starbucks both offer free wifi, and there are many locations throughout Tokyo. You must, however, register in advance.
7-11 "7 Spot" wifi registration (in Japanese) and a key in English for deciphering the page is here.
Starbucks free wifi sign-up page
Freespot.com is a map listing of wifi access points in Tokyo and can be pretty useful.
Your own phones
I tend to use the international package from my US carrier (AT&T), which allows me to use the Wifi networks of Japanese carriers. I have heard good things about T-Mobile for international packages but less positivity for Verizon. It is worth checking to see what your carrier provides, and reading forums about peoples' experiences with them while overseas.
Rental phones and personal wifi hotspots ('mifi')
There are multiple options for rental phones in Japan and I cannot vouch for particular providers. Below are some links for prominent ones, but I recommend doing your own research if you choose to go this route. Costs vary for phones with data capability or simply with calling, and for the type and speed of wifi connections. It is difficult for people on tourist visas to get a normal phone, but if you have a friend who is Japanese they can often add a wifi device to their existing contracts for a relatively cheap monthly fee.
Pururu (phone and wifi)
JAL ABC (wifi) and JAL ABC (phones)
Telecom Square (phone and wifi)
Japan Wireless (phone and wifi)
Global Advanced Communications (phone and wifi)
And Kakaku.com -- likely the cheapest, though the site is all in Japanese: Kakaku.com.
Free wifi out and about in Tokyo
The convenience store chain 7-11 and Starbucks both offer free wifi, and there are many locations throughout Tokyo. You must, however, register in advance.
7-11 "7 Spot" wifi registration (in Japanese) and a key in English for deciphering the page is here.
Starbucks free wifi sign-up page
Freespot.com is a map listing of wifi access points in Tokyo and can be pretty useful.