This is also my case.
You must know about the VPN and Great Firewall. Remember, you cannot use twitter, facebook, gmail in many cases if you don’t prepare anything.
Read at first: https://en.wikipedia.org/wiki/Great_Firewall
How to avoid the Great Firewall: http://matome.naver.jp/odai/2138191062800721301
https://getlantern.org/
And you can know:
https://en.wikipedia.org/wiki/HTTP_451
https://en.wikipedia.org/wiki/GoAgent
https://zh.wikipedia.org/wiki/Shadowsocks
Also, many of below are also available in Shanghai, but it must cost than Japan.