I get it in my native language, Swedish, which means that they are doing some kind of detection based on the requests your browser is sending, or based on your IP.
If you don't live anywhere near Japan, nor have configured your OS/Browser for this language, I would guess their system for detecting certain region-specific IP's is outdated or broken.
Comments
http://browsehappy.com/ is in English for me.
This is what I see: http://i.imgur.com/DRm13.jpg
I get it in my native language, Swedish, which means that they are doing some kind of detection based on the requests your browser is sending, or based on your IP.
If you don't live anywhere near Japan, nor have configured your OS/Browser for this language, I would guess their system for detecting certain region-specific IP's is outdated or broken.
Setting language based on IP address is... terrifyingly inappropriate.