When you use the free Wifi, that is most likely NOT encrypted.
So, please avoid using the sites that require you to log in, avoid using the shopping sites, and please change your private setting for sharing folders/files.
[Customizing Your Network Sharing Settings]
http://www.howtogeek.com/school/windows-network-sharing/lesson3/all/
Thank you and please share this with your friends in Kumamoto. Thank you!!