Change the apt-get server your device connect to

The first time I used the sudo apt-get command on my Raspberry Pi in China, I had a very bad connectivity with the apt-get mirror automatically selected so I had to find a way to force a direct connection to a specific remote server and this can be easily done by :

Browsing the list of mirrors from https://www.raspbian.org/RaspbianMirrors

In my case the closest one was in Japan from the tsukuba server.

Then you just have to edit the source file at /etc/apt/sources.list

sudo nano /etc/apt/sources.list

Add the line and add a # before the other ones:

deb http://ftp.tsukuba.wide.ad.jp/Linux/raspbian/raspbian/ jessie main contrib non-free rpi
#deb http://mirrordirector.raspbian.org/raspbian/ jessie main contrib non-free rpi
#deb-src http://archive.raspbian.org/raspbian/ jessie main contrib non-free rpi

TADA!!

Tell me if it worked for you.