Maho
What are some popular free wifi cafes / spots in Tokyo if I want to quickly get some internet access?
Akane
Try going to Starbucks or Tully's (another cafe). You'll have to login by providing your email address but it's free.
They also provide free Wifi at convenient stores like Seven-Eleven, Lawson, and Family Mart but their login procedure is more complicated so I'd go for the above cafes.
